Solar panel sounds like a good idea. I park mine for 6 to 8 months but I disconnect the coach batteries ground and have had no problems so far. I run the engine for 1/2 hour or so every 2 months also.
I found the way to get around this was to buy a class A toy hauler. Put my 2005 Goldwing trike in the back and off we go. When trike is out the garage is our bedroom. We love it'