I used to have 30 for Thanksgiving, loved it, but it was a lot of work. I finally developed a menu that everyone liked and so I did it the same every year. Some short cuts:
wash the salad greens the day before, wrap in a dish towel and put in a plastic bag in the frig. Dice up some veggies for the salad and store in another plastic bag. Use Newman's own balsamic vinaigrette on the day.
Microwave a bunch of sweet potatoes until really mushy. Put them aside to cool. Peel and mash with some dried aprictos and some bourbon or orange juice. Put in baking dish, cover and refrigerate.
Prepare your green veggie - trim green beans, or brussel's sprouts. Whatever you pick, prepare it to the point of cooking, put in a plastic bag. The next day, microwave the green beans or brussel's sprouts in a little water until tender. Grate some cheese or lemon peel over the top and call it done.
Instead of mashed potatoes, I always made colcannon the day before, put it in a baking dish, covered, and stored until the turkey was done. Cooks at the same time in the oven as the sweet potatoes.
Make your stuffing a day or two ahead, put in a large greased baking dish, cover and freeze. Take it out of the freezer when you put the turkey in the oven. When the turkey is done, it needs to sit for 20 minutes or so, long enough to cook the stuffing in the over and make the gravy.
Buy pies or assign dessert to other people.
I like to do the Pennsylvania Dutch thing of seven sweets and sours - little dishes all over the table with nice things I just pour out of jars: olives, pickles, nuts, applesauce, marmalade, salsa, pickled peaches or crabapples or picked grapes, whatever comes to mind and looks pretty in a little dish.
So most of the work gets done the day before - I even set the table the day before and set out all the serving dishes and serving utensils. This year, however, I'm not doing Thanksgiving, so it was fun to read your thread and have a vicarious Thanksgiving.