If you are doing a lot of winter camping, then your best bet with solar is probably the solar panels you mount on stands and not mounted on the roof. You want to be able to get the best solar angle and snow will slough off or brushed off a lot easier.
Our panels are all mounted flat on the roof but we have enough panels for winter camping at any time of year in the SW (temperatures can get down to 10F)
Climbing on top of a TT or 5th wheel when it is covered with really slick snow to clear the panels can be really dangerous. Tried to do this two years ago with 10" and I started to slide off just sitting down. Extended the telescoping ladder and brushed the stuff off from the side.
We have only tied into line power once in the last two years and have not used our Honda 1 kW. Have to say the Champion 4kW we had up to five years ago was great.
Reed and Elaine