Go for it!!!
You can get lots of themed paper plates, drinking cups, cutlery, and even table covers and napkins that are great for large family gatherings for Thanksgiving and any other gathering.
It will make it so much easier on you with all the prep. for that amount of people. There will still be a lot of use for the dish washer even then, with all the cookware and veg dishes etc.
My DIL has always done this, and also serves the meal buffet style. She even has a couple of trash cans she keeps just for such times and makes sure everyone knows where they are to dispose of their own plates and stuff. She gets to spend more time with family and guests, and everyone always has a great time. It is one of quite a few ideas of hers I have adopted.