Small used Class C--good idea or false economy?

I could live indefinitely in my 24' class C. When I return from vacation, it is not because I'm getting tired of living in the small space.

I think you will have easier time finding a good one at $20K plus. Take your time and find something nice.

Wintering in Montana would not be easy. I find mine is fine down to the low 20s or so as long as it warms up to the 40s during the day.