A couple of thoughts...inside is best, especially in MA where you'll have snow sitting on it for months at a time. You don't "have" to have power, but if not, I'd remove the batteries and take them home. If you have power, you can leave them in the coach...keep properly filled with distilled water. The engine gurus say do not start the coach, if a diesel, unless you will run it and bring it up to operating temps. Also you'll have to winterize the water system. I don't winterize it, but since I have very reliable power, and live close, I drain all the water and place 60 watt light bulbs in all the important areas (washer/dryer, Aqua Hot, fresh water pump, refrig, etc) and put anti freeze in the toilet and P traps. As you noted, covers are a hassle.
2014 American Eagle 45T
Pulling a Honda CRV