Let your casserole sit out at room temp for about 30-45 minutes. I would probably reheat it at 325 for about 30-45 minutes. But if you are going to fill your oven up with casseroles plan at LEAST 1 hour.
Have a great Thanksgiving and thanks for stopping by jcais!!
I'm with Wasabi on this, as I would nuke rather than oven reheat. I would divide the leftover into serving portions and nuke that way, as otherwise it would be difficult to get the food in the center of the pan heated. Also remember, no aluminum items in the microwave.