I was thinking of the long boring hills of Vermont being the bad part. Not necessarily the traffic in the cities down south. But I can see that part being really bad too. Since you guys are Mount Snow travelers, you don't really get into the really long haul part of I-91 which is the central 1/3 of the interstate from a couple exits south of WRJ to StJ.
I can see how things can get a bit "boring" once you get farther up into VT. Exits are few and far between and there's really not much around.