We use to do that all the time in Colorado. In breckenridge some people would just stay in the ski resort parking lot. They just said if it starts snowing you will have to move for the snow plows. You should talk to management and see if they would let you do that. We had a rv resort right down the street so we stayed there. Heating you should be no problem at all. We did this with a Class C. Seems to me if you show up after there closed why would they care if you were going skiing in the morning. But who knows maybe they have signs posted.