IMHO dry camping and high power draw appliances do not go hand in hand. When dry camping we never use the microwave or the AC. Well, just once when the temps hit over a hundred. But generally the whole idea is to get by with what we have. Which if your properly setup is easy to do. Stove top coffee maker, gas grill and a two burner gas stove outside takes care of 90% of our cooking needs. The rest is done inside on the stove or oven. As for a replacement microwave, take some measurements and go to your local big box store and find the one you like that will fit the existing space.