Our camping vehicle before the MH was a 1992 GM 2500 van pulling a pop up. The first thing was the starting motor, which failed in a parking lot 3 blocks from home. I managed to replace it myself right where it was parked. At about age 20, we lost the heater core while camping in Jasper Park. We limped to Rocky Mountain House where we found a nice little garage recommended by Canadian Tire. They couldn’t fix it for two weeks and the estimat was $700. I asked if they could patch it up so we could drive home. They did - just connecting the input hose to the output hose. I managed to replace the heater core myself with some advice from friends. The next year the alternator and water pump failed. The mechanic friend replaced them for me. No problems since then except routine brake work.
Our 2004 class C purchased in 2008 has not seen a garage so far. I only recall replacing the engine thermostat and belts. Also a broken house drain pipe elbow and some roof leaks.