I've read almost all the Grafton mysteries.
If you want to stick to an RV theme there are two authors worth checking out. The first is Nevada Barr and her series featuring Anna Pigeon, a national parks ranger. Nevada Barr is a real ranger and she features a different park in each mystery.
The other is Sue Henry's Maxie McNabb. Maxie is a retired woman who drives a motorhome alone and of course solves mysteries. One book is The Tooth of Time.
Right now I am reading a series by Victoria Houston. The stories take place in fictional Loon Lake, Wisconsin and the main characters are a retired dentist, a women sherif and a fishing guide. Dead Angler is the first in the series and all the main characters are avid fishermen be it muskie bait casting or trout fly fishing.
2021 Advanced RV 144 custom Sprinter
2015 Advanced RV Extended body Sprinter
2011 Great West Van Legend Sprinter
2005 Pleasure-way Plateau TS Sprinter