I would not leave the slide out during the winter.
Now can you plug into shore power and bring the slide in? I have never used just my battery to move the slides in/out, I am always plugged into shore power. My two pervious 5er's required shore power to move the slides and I just carried this over to my CC 34RL. Also make sure that the switch in the service bay is not turned off to move in the living room slide.
Hope this helps?
2016 34RL CC; 2008 Ram Mega Cab 2500HD, 6.7L, 68RFE 6 speed, 4X4, Smarty S67