Can I mix the ingredients for corn casserole and keep it in the refrigerator over night before I bake it?

I wouldn’t hesitate.

It would probably be okay. You’ll likely need to increase the baking time a bit, since it’ll be starting cold.

I think it should be ok, but I personally would make my cranberry mold ahead of time if I was going to do one of those that you listed ahead of time.

Sure it’s OK. Cranberry sauce too.

Yes, it should be fine. It might be worth adding the butter and sour cream just before baking so that it doesn’t get soggy.

Stuffing can be prepared in advance. So can cranberry sauce. If you are making mashed potatoes, they can be boiled in advance and kept in the refrigerator overnight.