You may also want to rent a 4x4. The roads are all 4 lane, heavily snowplowed and well maintained. BUT if there is a big snowstorm, it can be pretty slow going.
Nobody is trying to scare you but you do need to be prepared.
I also wanted to mention I have ripped through these roads at 80-90 miles per hour in a Corvette in the middle of winter too. Nice sunny day, lots of snow everywhere but on the roads, and little traffic. Just depends on the weather.