Cinnamon rolls, banana bread/muffins, egg casseroles.

Any bread pudding, muffin, or quiche (or just pick a few up from Whole Foods) can be frozen and popped in the oven the morning of your brunch. Par baked croissants are also lovely (paired with various jams, nut butters, and nutella. And maybe some deli meats and cheese for sandwiches. People will love it). Remember that bacon is easily cooked in the oven and won't be turned down by those who might be nursing hangovers. Fruit salad can be thrown together quickly (or brought by one of your local guests). Yogurt is another easy option that a lot of people would appreciate.

Congrats on your wedding!

Another hitch I forgot to throw in there: we are gluten free (though most of our guests aren't) and would love to have a spread that is not heavily laden with baked wheat goods.

I love the idea of a more 'Italian' style breakfast with meat and cheese!

I would love to do an egg casserole or quiche, but I was under the impression that eggs didn't freeze well, which is one of the reasons I submitted the question in the first place. Is there some way to do it well that doesn't cause the eggs to release moisture when defrosted?

We had great results (and many compliments) with Giada's blueberry french toast casserole at a brunch party we had a few months ago. I made it the weekend before, froze it, then baked it off that morning.

http://www.foodnetwork.com/recipes/baked-french-toast-with-blueberries-recipe/index.html

what about a granola & yogurt bar? it's not something to freeze, but you could make/buy some really nice GF granola a week or so ahead of time and then buy a few tubs of yogurt and serve with nuts and fresh fruit/berries. you could lay everything out buffet-style and let guests build their own breakfast parfaits (which would be nice for an open-house style gathering). you could even send guests home with little bags of homemade granola as party favors!

I've had great luck freezing quiches and egg bakes. Crustless quiche would also work great for any others who are gluten free. Best wishes for your wedding!

My favorite brunch item that encourages people hanging out and chatting is waffles. Little kids love making waffles, you can have all sorts of toppings, that sort of thing. Even, better, you can make the batter up to two days beforehand. But obviously, some homes and/or numbers of people coming for brunch make this tricky.

I'd complement things with fruit - and if you do happen to have in-town guests, this is where I would ask them to be unofficial hosts and cut up or wash lots of fruit. It's not a huge culinary responsibility, just one of time (2 hours or so) -- provided your brunch isn't too early and no one drinks too much, it's something that could really be quite helpful.

Also---mimosas. Yum.

Hash is great for the night before. If I make corned beef or sweet potato hash I usually serve with poached eggs the next day.

Muffins or any baking can definitely take place ahead of time.

A frittata with spinach, rice, cheese, onion, and eggs.
A fruit tart with almond crust.
Baked oatmeal squares.

If you don't want to bake gluten free, but don't mind providing gluten products to guests, then bagels with cream cheese, lox, and jams are great.

Rumaki or other bacon wrapped items are simple to make ahead and freeze. They bake easily.

Ham biscuits are a standard for southerners at such occasions. Nice touch if you have someone to carve away and put the ham into homemade biscuits as they are needed. You can do the same with roast beef.

Cookies and bars can be baked ahead for a dessert item, also homemade candies.

Searching my head for a soup that would fit in. Many can be made ahead and defrosted. Chili?

PS--If this is the day after your wedding, even if you don't hire a caterer, consider hiring a couple of server/helpers. i admire your bravery being a host so soon after a big event!

Mediterranean chopped salad from America's Test Kitchen (more lunchy than brunchy, but a crowd pleaser, and gluten free)

Oh no Samantha....don't do it! My wedding was about two-thirds out of town guests, so I invited everyone over the afternoon following the event for leftover cake. It was too stressful! I was exhausted from the day before and the house was a mess with presents and other junk. If you can manage it -- have someone else host!

How about making more of whatever meat you will be serving at the wedding, and have cold cuts the following day for brunch? Or you could make some rustic terrines - serve with some cheeses, relish, bread for those who want, and fruit on the day.

scones freeze great just make them freeze before baking --have someone like a parent bring fruit salad--i usually make french toast casserole and an egg one usually in muffin tins individual---quinoa salad--meats and cheese--different juices and booze so people can make their own mixed drinks with lots of toppings--bloody marys/marias and mimosas

Exactly HOW many people are you talking about?
If it is over 20, its another major event.
But if you are still keen to go ahead and do it...
Ask one of the out of town guests to collabate with someone local, both of whom know each other and were at the wedding to organise a Brunch BBQ.
Post party breakfasts are fun. Everybody sticks in x ammount of money, a decendance on the local supermarket/dairy/etc, head back to venue and fire up the barbie, break out the chilly bins and such.
Keep it very casual.
Congratulations on your wedding and have a great life.

French toast-I have a great recipe on my blog. It freezes well too!

We hosted a (largely) gluten-free brunch for about 50 the morning after our wedding. It was a great event - but it was hard to self cater, I just found that there was not enough time that morning.
To make in advance/freeze: You may be able to find some gluten-free breakfast bars that would freeze or just keep well for a few days, we ordered some great ones from Bittersweet (a GF bakery in Minneapolis).
Also, I'm thinking that waffles freeze pretty well and lend themselves to being GF. If you have some gluten free ones that you like - perhaps you could make and freeze a giant stack in advance to toast on the morning of the party. I would suggest testing this before you make too many.
Not to freeze: smoked salmon and GF crackers (maybe with cream cheese) goes over very well at a brunch. To make it a "bigger" item you of course can do this with gluten free and/or regular bagels. Yogurt and Granola are great. Fruit salad (we ordered ours from a local grocery store).
Congrats & Good Luck!

Congrats! So exciting! I have a couple of great go-to crowd pleasers: Mini Potato Crusted Quiches made in muffin tins and Raspberry and Lemon Stuffed French Toast. Totally great make-aheads, beautiful enough to make your guests feel special, and easy to eat at a party (Bonus: Gluten-free!). Best wishes and good luck!

http://www.freshnessgf.com/berry-stuffed-french-toast/
http://www.freshnessgf.com/potato-crusted-quiche/

A cooked quiche freezes extremely well and always goes over well. I would reccomend making the quiches in a mini muffin tin, chill them in the tin, then pop them into a ziplock, they can be easily reheated to room temp on the day of and are a great size for a party. Someone also mentioned scones, I would freeze those, uncooked, and bake the morning of the event, you can prepare the dough and pre-portion them. A yogurt bar with homemade granolas and fruit is also fun and festive and a healthy alternative. You can make mini yogurt parfaits in advance with fruit and granola, they look realy nice in small mason jars.

As a person who helped with 7 out of his 9 sisters weddings. DON'T SERVE LEFT OVERS!!! People will be sick of the dinner food. You want something light, a lot of people would most likely be hiding hangovers and sour muscles from dancing all night. Stick to light foods, fruit mixes are a good start. There is a recipe on here for the blitzes, try that, they can be frozen. Bacon and sausages can be cooked the days before, frozen and than warmed in the oven, low heat. It'll also make the house smell really good. Basic granola and yogurt. Less mess you have to prep that morning, less you clean up.