It’s really more akin to camping, but I stay in my 4Runner for about 3 weeks each year. I drive from MN to VT and ME to see my brothers, other family, and some friends. Because they aren’t all in one area, I have to be a bit mobile.
Also, I’m not a huge fan of hotels and the “traveling populace,” so if I can avoid both, so much the better.
National and state forests end up being my lodging. You have to plan a bit and know what’s going to be open at the time of year in question. Each day I hit a truck stop, where you can rent a (usually) clean private bathroom with shower (behind a secure, locking door) for about $10.
It’s fun to do, but it does get old. If you were to live in a vehicle full-time, I think you’d need periods under a roof to break it up.
A better option might be to have a very inexpensive house that you can come back to, so you always have a home base. Located in a low cost of living area with low taxes, small, etc. Go out on the road for a month or more, then come back for a while.
This is assuming you either don’t need to work - like if you’re retired - or can work on the road. Also assuming you’re single and without kids, obviously.