We just made the trip a week or so ago. We towed a car and the motorhiome is 35 feet long.
On the way to Bennington there are lot of small towns to go through and a lot of construction with one lane traffic so you have to wait before your direction can be routed onward. As I recall there was some construction on 9 also.
It's doable though, just not much fun.
It is quite a bit shorter than the other routes according to my navigator.
However when we go back west in a few weeks I told her to route us a different way.
In the past we have taken the Mass Pike to 290 through Worcester to 495 to 3 through Nashua to Manchester and then 93 on up to Concord. It's probably best to miss rush hours going that way.
We are at the Cascade Campground on 106 in Loudon, site 256. Stop by if you have time.