I live in Wyoming, about 4 miles from I-80 as the eagle flies, about 6500' elevation. We typically have our first snow of the year the week of Sept. 30, so you definitely should plan for weather delays - if you get through without them, you can spend some time sightseeing. Motor homes do not do well in snow; I have driven in it and gotten there safely, but every time was a nerve-wracking experience and could have had a less positive outcome. Even if it doesn't last, poor visibility and slick roads make for lousy driving conditions until it is over. Also watch for high wind warnings, our Wyoming winds regularly blow semis over and you don't want your MH to become one of our blown-over statistics. I-80 is a pretty easy drive, just one high pass (8100') and only the western side is steep, but it's a largely boring drive most of the way and the Rawlins area is notorious for problem weather.