done that a few years. This year and last we ordered a meal from Harmons. I think it is too late to order from a Grocery store, but it makes Thanksgiving so much easier... plus you have plenty of leftovers, unlike when you go out.
I know many hate on Chuck O Rama, but it is a decent idea for a large group on Thanksgiving. Get there early, or plan on a long wait (Actually probably both). It is crowded enough that there is good turnover on the food, and they have all the classic Thanksgiving foods and a few other options.