make ahead, main dish, easy to transport
How about something like a pasta salad, or mac and cheese type dish with bacon bits? pretty simple, and easy to reheat in a microwave.
Also, keep in mind dishes that can be served from a crock pot....that way you are freeing the microwave for other dishes. One of our "go to" dishes is a spicy link Italian sausage with a tubular pasta like mostacelli or rigatoni in a marinara sauce. It holds well, it is satisfying, and it goes well with all of the sweets floating around!
This is a nice one. Can be made the night before, chilled, and served at room temp. Vegan and vegetarian. Leave off the almonds for those with nut allergies.or serve in a dish on the side. IMHO I think the dried cranberries are very optional.
Most people love lasagna at these parties - too difficult (time wise) to make for a small family. Fully cook it and pop in the fridge overnight. Then just heat up in the nuker. You can even buy a good frozen one and transfer into one of you dishes and tell everyone you spent hours and hours making it.