breakfast casserole for 100 teens
I have someone gotten myself in charge of breakfast for a youth conference. I was thinking of strata as the main dish but am open to other suggestions. My question is this - we don't have enough refrigerator space to make 10 (?) big pans of this and refrigerate them overnight. Should I make them up in the morning (not much time to soak), leave in the cold oven overnight, or make something else?
Under NO circumstances leave out overnight.

You need about 6 of those half-pan size aluminum pans, assuming you will have some additional foods. Do have some yogurts and hard boiled eggs no matter what else.

How about the egg, cheese and hash brown type casserole that can be made up that morning and doesn't need to soak. Make some (1-2 pans) meat free for the vegetarians in the bunch, the rest with ham.

thanks - do you have a recipe for the egg/cheese/hashbrown casserole?
Here is for 100. It makes 32 quarts:

* 16 (2 pound) packages frozen hash brown potatoes, thawed
* 16 pounds pork sausage OR diced ham
* 16 small onions, diced (5-6 pounds)
* 80 eggs
* 8 cups milk
* 2 tablespoons and 2 teaspoons onion powder
* 2 teaspoons garlic powder
* salt and ground black pepper to taste
* 12 pounds shredded Cheddar cheese, divided in half (can use jack, Mexican blend, etc).

Preheat oven to 350 degrees F (175 degrees C). Grease the baking dishes. Place the hash brown potatoes in the bottom of the baking dishes.
Cook the sausage until crumbled, nicely browned, and not pink. Drain.
Meanwhile, whisk together the eggs, milk, onion powder, garlic powder, salt, and pepper, and pour over the potatoes. Layer with half the Cheddar cheese, the sausage mixture, and the remaining Cheddar cheese. Cover with aluminum foil.
Bake in the preheated oven for 1 hour (75 minutes if the dishes are deeper). Remove covers; return casseroles to the oven and bake until a knife inserted into the center comes out clean, and temperature is 180 in the middle of the dish. This can take 10 minutes to 30 minutes depending on how thick the dishes are filled.
Let stand for 5 minutes before serving.

By the way, when I make this for adults, I often add veggies, maybe bell pepper, or mushrooms, sliced or diced tomatoes, diced green chilis.
Thaw the potatoes in the refrigerator, not on the counter. To make homemade hashbrowns and freeze ahead, you can use the recipe in my OAMC potato plan: