Is this even possible? December in New England?

Not sure about the area in discussion but I know of at least one in Michigan that is open year round. They only have one loop they keep open and it's all longer term (month or more) stays.

It can be done and we've stayed thru late November but it's a pain in the rear. Make sure the furnace is in good operating condition and you have heating systems for the fresh, gray & black water plumbing.