Boondocking seems fun but also seems like it would get exhausting. What about picking up a lot at a tax auction or even on the regular real estate market? Taxes would be low since there's no building on it, even in my state of NY. One could even put in a pole and electric service. City sewer and water might even be available depending on how rural the site is, or put in a well and holding tank or septic system.
Lots of times they sell these building lots cheap b/c they are too small for a house to be built on without a variance from the town. Too small for a house is fine for an RV!
Pick one up in the south for the winters, and one in the north for the summers.
If one got the urge to wander and see new sights, one could still boondock for as long as they wanted before returning back to home base.
I was thinking that setting up an RV spot behind my house with a nice driveway back to it, and renting the house as an income property might be a good way to go during retirement. I guess you could do the same thing with a house purchased only for that purpose. Buy it to rent it out, while also providing a parking spot for your RV nearby, and income.