I think the advice to try renting is a good idea in your case. Take a look at
rvshare.com.
Sounds like your going to have to get over not being comfortable driving anything bigger than a Yaris before going further.
Living in an RV in winter is not the best situation for a young child. I would think you could find a new place to live by just doing road trips on school vacations.
Gas costs a lot of money as does propane. A 17 year old is not going to like being confined in a small space with a child, a dog, an adult and 2 rats. What does he have to say about this plan?
Hope you find the path your looking for.
