Anything less than 60 watts is more of a battery maintainer for storage and no good for suppling power to a refrigerator or reasonably fast charge to low batteries. Your best charger is the vehicle or generator.
As far as camping, there are people on the site that know more about Colorado and Utah. I stayed at a nice first come first serve camp along the Colorado river in Moab...there is a bunch of them there that cost under 10 bucks a night if I recall.
Great Basin NP is a fantastic mid-way spot to camp between Utah and Nevada. You could go south from there to Arizona then back up through Death Valley and back over past lake isabella into the central ca valley
For camping out here in Ca you can check my my site
but many areas are closed off to winter. Most any western sierra foothill lake will be nice at that time of year. Merced River Canyon is bad ass and close to Yosemite (visit my site)
Ski sites are on most all the major highways up into the sierra's west slope between 80 and 41 plus a few on the east. It will be cold. 80 will probably be the only pass open depending on the snow pack. Otherwise you'll have to go down south to get over.
Figure out a basic route and post for help in the trip section and you'll probably get a bunch of suggestions.