The best thing I ever did was move more than a day's drive away from where I grew up. No regrets at all. If U of U has one of the best programs for what you are interested in doing, go for it. Time to get away from the next and see how you do on your own. You can always move home at anytime if it's not working. I suspect it will though.
Vermont wouldn't suck either. Not nearly the quality of snowboarding, but closer to the teet if you must. The most important thing is the quality of program you are entering.
If you do go out of state, plan on becoming a resident. Get your driver's license swapped over asap, and do whatever else is required for residency. Get your tuition costs down as soon as possible. I am sure U of U is cheaper for Utah residents. Not sure on Champlain.