Do the slides cover furnace vents when in?
I don't see any reason to leave the water connected. With the slides in, you will be heating less space and using less propane, although if power was available. I'd likely use electric space heaters. I would also make sure the propane tanks are full.
Mike and JoAnne
Montana Summer / Arizona Winter
2016 Prism 24G /2002 HitchHiker 38LKTG
ACME EZTowing a 2015 Chevy Sonic RS Hatchback