Welcome to the site!
Is the truck overheating at all? If you had a radiator leak, I think if you were in a lot of traffic you'd overheat.
Have you checked the sensor itself..sometimes that can go bad.
If I lived near the rockies I'd probably opt for 4wd too. I'm in the Washington DC area and we don't get that much snow, so a 2wd with decent tires would do fine.