I need to make this ahead. Does that seem okay and how best to re-heat?

Like a lot of Chinese food, mapo tofu tastes even better the next day. I usually reheat by putting in a wide, but shallow bowl, cover with a paper towel or clean cloth towel and reheat in the microwave. If you don't have or use a microwave, heat in a skillet, covered, on low until it's heated through. Stir the tofu as little as possible.

Why don't you prep, measure, cut etc. so all there is left to do is stir fry. It would take as long to reheat as stir fry