I have a well insulated Class A and I was living in it while I was between houses. I was supposedly in a warm climate when a snowstorm hit. The temperatures go down in the single digits for a few weeks and there was about a foot of snow on the ground. I will tell you that it was not a lot of fun to be in an RV in those temperatures. You go through propane like crazy for one thing. Even though we used less propane than anyone else in the RV park, we still used a lot of it. And we used electric heaters as well. It is just plain expensive to heat an RV in the winter. Even the best insulated RV is not anywhere near as well insulated as a house.
I understand your desire to go skiing because I love skiing as well. You may want to go somewhere like St George Utah where the weather is good all winter and you are an hour from the Brian Head ski resort.