We are preparing baked potatoes for a crowd of 450 in two days. Is it OK to go ahead and wash and wrap the potatoes now?

I would wash the potatoes, but wait for them to dry before wrapping with foil. Now…I have not wrapped potatoes in foil to bake for twenty years because of the final results. Potatoes are about 80% water and 20% solids or starch. Foil wrapping before baking traps in the moisture so you get a wet skin and a soggy interior. The only time I recommend foil is if you are camping and want to put the potatoes on the coals of a fire.