In this post in the Van Life Q&A, a user asks:
Considering a cross-country road trip in a rental RV
It is approx 5 solid days of 8hr/day driving each way (not including stops for meals, etc) if you go pretty much straight across to SF. I don’t know that I’d want to do this in 3 weeks, it doesn’t give you that much time to explore and much of your time will be spent in transit.
Then there’s the mileage charges for rental RVs that are killer in terms of cost. You’ll be 8000 or so miles worth on it, maybe more or less depending how much you are going to drive around.
I’d suggest one of these ideas instead:
* Fly somewhere and rent out west and explore the areas you want to explore there, return the RV and fly back.
* Just rent one locally and explore some spots around you that you want to explore.
* If want to do both coasts, rent one locally first and do that part then fly west and do that.