Leave Slide In or Out
I bring mine in and raise the thermostat a few degrees, mainly for the reasons stated but also to have less of a "foot print" of cooling loss thus reducing the work load on the air conditioning units. The loss factor is pretty high with the slides out continuously, so why not ease that load when possible.
2012 Dodge 3500 Cummins Crew Cab 4X4, "Decluttered" and Tuned/2013 Forrest River Viper XLR 390V10 Toy Hauler/2012 Harley Davidson Ultra Glide CVO.
Full time RVer.