What is the best way to de-ice slide-outs

We camp at 6,000 feet in October and November for about six weeks and it is NOT anywhere close to an improved campground, not even a USFS or BLM campground, let alone running water. We have no choice but to extend the slide-outs. The dealer, knowing our camping lifestyle, recommended that we NOT install the slide-out toppers, as the toppers would not help prevent the snow and/or ice from accumulating on the slide-out. Their recommendation was to sweep the snow off as often as possible but they had no solution for the ice. When it gets below zero, it is a whole new ball game.