One thing Wife and I did was sign up for a couple of campground memberships.
These memberships give you access to the company's campgrounds for a flat rate a month. depending on the package 2 weeks in one week out (or 3 and one, I had the basic) As a result with two Campground about 60 Miles apart summer I paid about 100/month for parking (That includes the gas to shuttle back and forth) and abou 200 in the winter (3 campgrounds forming a triangle 17 miles on a side drive time)
You can often buy a membership for reduced price via one or another brokerage house by the way ... one of mine is so listed (the other is not) You can google for the brokerage places.
Or you can take a tour and pay full price.
I suggest at least one membership if only to cut down on the cost
Plus of membership.. Low cost parking (Generally around 50/month) on the 2/1 plan. Downside. 50/month if you use it. and 50/month if you do not. You still have to pay.
Downside two. The one I kept the "Jewel" park (about 3 miles from where I'm sitting) is amazing. Very nice, very modern 5 swimming pools for example.
The other parks in this system are good. but not that good.
The other park most all the campgrounds need a bit of 'er.. TLC.
So look before you leap.