I drive that regularly in the winter, and my advice is not to drive over Soldier's Summit in the dark if possible, especially in a storm. It is wide open territory with bad visibility, high winds, and very little road marking. In a snow storm the semi-trucks blast past you at high speed and visibility goes to zero. If you stay in Price, you can get to the Snowbird parking lot in about 2 hours. I'm no pussy, and have done it many times at night, but IMO it is rather sketchy, even in good conditions. Once you get on the interstate, use the commuter lane on the left, where you can go 70-75. Everybody speeds once you get to Spanish Forks.