Why not just gravel all around, properly compacted? Many campsites (and roads) are gravel, and they work just fine, even with much more traffic than you'll see.
I park my class C on plain old dirt next to my garage. (Technically the low side is on ramps on the dirt so as to make it approximately level.) This started out as somewhat scraggly lawn, but the grass underneath the RV doesn't get much light and isn't really thriving. So far, this has not been a problematic approach in the least; it helps that the area is appropriately graded and doesn't tend to get soft or muddy.