Back in my working days I used to work at around 10,500-11,000' and found it noticeably warmer at those elevations than down in the valleys 2,000-3,000' lower.
As was mentioned you just need to dress for it. Riding a ATV with tracks on it would be no colder than riding a snowmobile up there. Granted you are not going to be doing it in jeans and a T shirt.
I'm glad to hear that the tracks work so well on a ATV. Companies where I worked would put them on their trucks and SUV's and they found that they had to stick to groomed ski trails unless they wanted to call the snow cat to get towed out.