Yikes. So I'm thinking there are two major issues to deal with getting there. Keeping warm....which is the lesser of the concerns, given a generator, furnace and heaters, tank heaters, water inside the coach space. The other is the roads. Do you look for windows of opportunity and check road conditions all along the way? We are going on a coast-coast-coast trip this spring/summer and I might be a little more brave after that, but at this point I'm impressed!
You must be having a ball in Arizona...our last trip there (not in an RV) we visited Sedona (side trip from our base in Scottsdale) which was beautiful, but they have a lot of roundabouts in the main road. I wonder now about how RV-friendly those are if we ever go back.
When you do get back to Wisconsin in May/June you should realize that many folks (us for one) have that area on our must-see list. We'll be doing Sturgeon Bay and Lone Rock this May. I wanted to take in Lake Geneva as well, but time isn't on our side.
If you make it out to the Clarkdale, AZ area, the Verde Canyon Railway train tour is really nice.
http://verdecanyonrr.com/ - Mike