Heh. Back in September I rode through Blandford, MA on the second day of a tour from Brattleboro, VT to Philadelphia. I came from the west on U.S. 20 to Russell and then took Blandford Stage (which becomes Russell Stage) up to MA 23 in Blandford and continued west on MA 23 through severe rollers. Getting up to MA 23 required 1,100' of climbing in 4 miles. It started off pretty gentle so I thought "This isn't as bad as it looked on Ride With GPS." I was eventually in for a rude awakening. When I finally wandered into a store near Tolland Reservoir the cashier asked me how I was doing. I looked at her and replied "I've felt better." Your way looks slightly easier, but it's still a bear. In any event, MA 23 could have moderate traffic, but there appears to be a good shoulder.
If you look on Street View, you will see that U.S. 7 has some traffic and little or no shoulder in places between Pownal and Bennington. You might want to stick with parallel side roads, which are also visible on Street View. For me, the charm of New England is found off the beaten path.
How do you plan to get back? Reverse direction? The reason I ask is that Amtrak's Vermonter train has walk on bike service for a limited number of bikes. No boxing required. I used to get to Brattleboro for the start of my tour. Arrived right on time. You could ride over to one of the station along the route and tale the train home. It's my understanding that the service is very popular (several people got on and off with bikes at various stations during my trip), so reservations well in advance are strongly recommended.