If you aren't needing warranty work, there are any number of independent shops that work on trucks and motorhomes; I have yet to have any real difficulty finding one when I've needed it. Often they don't advertise all that heavily or have facilities that are immediately obvious from the main roads, but can be found by asking around. People with box trucks and step vans and shuttle busses need to get them repaired from time to time, after all, and it's not much different working on them as on a motorhome.
For warranty work it's maybe harder since you need a factory authorized place.
