Really Les, you hail from Brandon and you're worried about driving I81? It's not like you're driving over "Lincoln Gap"... All kidding aside, I did it last year in February with 8" snow storm that turned to ice in the mountains. The DOT boys did a very good job and we cruised right through. Our biggest problem was finding a campground; all the usual parking lots were posted in that area. My wife believes in following the rules and overnight parking was out of the question.
BTW: I grew upon Birch Hill Rd. Forestdale VT.