Could be in the states next month either Washington or Chicago. Thinking of taking 10 days or so and driving to Vegas possibly thru Kansas and adding an NFL game in somewhere. Would any of our American brethren recommend it during November?
Been a decade since I was in the States but have driven the west coast and Chicago to Seattle before including snowy conditions before just wouldn't be sure on trusting a rental in some of those conditions.
We did Denver through to Vegas, including some of the national parks in Utah. (We only went to Vegas because it started snowing heavily for the last scheduled park.) Moab is a good spot for exploring that aspect of the state.
Car hire in the USA will try to tell you that anything but an SUV is not suitable for the Rockies. We ended up with a Suzuki Swift despite their protests (which is the same model we had for many years in the Alps) and were perfectly fine. Rentals will have winter gear (chains) anyway.
You could try the Broncos (home against the Raiders) but that is full-on rivalry so tickets might be tough to get. Also maybe try the college games (Buffs in Boulder, CSU in Fort Collins, or Air Force in Colorado Springs).
Rather than going through Colorado, avoiding the mountains if the weather is bad could lead you into Wyoming on I-80 and then to Salt Lake City. Wyoming is flatter but has its own 'western beauty'. Note that parts of southern Utah and northern Arizona are getting into the weirder Mormon areas (fundamentalist polygamous communities).