We went toadless on our retirement trip - 6 months 16 states and 6000 miles - and rented a car from Enterprise when we wanted to explore or get supplies. Rental fees over the trip were $3000 - the second highest expense. In addition, we found that we were selecting campgrounds based on their proximity to the Enterprise pick-up radius. Not the best criteria.
This also exposed the underside on the Enterprise business model. A lot of the offices in non-urban locations are simply a branch office in a body shop. They are not manned on any schedule and sometimes I would need to drop off with no one there to check for damage. The pick-up drivers are contractors and not willing or responsible and the body shop people wanted nothing to do with it.
With all that experience of going toadless, we bought an Equinox, put a Blue Ox base plate on it and I found a Blue Ox tow bar and an RVi2 brake on Craigs List. On our last trip out west, we did a lot more exploring.