We've always ued our campers in the winter driveway camping. Slides are out. But when "they" are calling for snow, I pull the slides in until the snow fall ends. That's another reason why we always opted for a camper that was functional with slides in.
I probably do not need to pull the slides in and they can handle snow with no problem, but if something ever happened and we needed to bug-out fast, and there was snow on top of the slides, it would not be a very fun activity removing the snow to get the slides in. I'm always thinking pro-active with the camper. I try to keep it, always, ready for travel, even in the dead-of-winter.
Slides in if predicting snow, or when not using it. Slides out when using it.