Just got back from a 1,000 mile winter road trip from Long Beach, CA to Carson City, NV (visiting my daughter after Christmas). My black/black/black 2009 cab made the trip in great shape. I found I could cruise easily at 80-85 mph. I did have to downshift to 4th for most hills, and on two steep grades I had to downshift to 3rd. However, I could still go over 60 mph in 3rd, and over 70 mph in 4th, so it wasn't a big problem. I avoided roads with snow tire/chain requirements (which required an overnight stay in Bishop CA on the way up), but I did hit a couple of snowy patches, and the car performed well there (having lived in Northern NV before, I know you have to slow down for snow).
The car warms up quickly, even in sub 30 degree (Farenheit) temps - and that's when the heated leather seats come in VERY handy. Driving in the mountains, the Sirius radio stayed on the whole way (tuned to the Blues channel, of course). I also got to use the fog lights, as there was dense fog around Mono Lake on the return trip. All in all, a great trip!