108 is a North/South route, doesn't seem like a logical choice given your route plan. Take Route 2 across the state (starts in the islands, NW corner of Vermont), and then continues through VT to NH border east of St. Johnsbury. it also spits you out in NH near where Mt. Washington is, I believe there is a scenic vista in West Danville where you can see the Presidential Range.
Agree upstate NY is great riding roads. I have not been back in many years since moved away but if have a chance go to Lake George and follow over to VT on to RT2 as it is great...Have a great trip