What type of rig and are you talking about maintenance on house or chassis? For house problems, their are mobile RV techs (and also for some chassis problems) that some RV Parks will allow to come and work on guests rigs.
We don't do maintenance, we worked long and hard to be able to enjoy our retirement and that does not include a 6 gal oil change, etc. For morothomes, most places that do maintenance work/reparis have a place for you to stop for the night, often with power and sometimes water. They take the rig in the morning, push it out in the evening. We spent 6 weeks at the Coach Care facility in Elkhardt, IN, waiting on parts to get our rig fixed. Did lots of sightseeing during the days, laundry, shopping, etc.