How do you re-heat baked potatoes when they were served two days prior, and were wrapped in foil when they were baked?
Baked potatoes wrapped in foil should be properly cooled and stored if left over. I recommend that they be taken out of the foil and stored in a metal or glass pan, then covered with cling wrap or foil, once they have cooled down to the refrigerator temperature. To reheat, uncover and bake at a lower temp, 275 degrees F until the internal temperature is 185 degrees F.
Note these cautionary posts:
And some other suggestions for doing a twice baked potato: What to do With Leftover Baked Idaho® Potatoes
Or other baked potato questions: All Things Baked Potatoes