#3 for Arrowhead Marina. Actually the Albany/Troy area is directly on your route to Boston, and the campground is an easy on and off the NY Thruway. We live about 45 miles west of Boston and we use that campground as we travel to western NY. I concur that the Lake George area is great and has a lot of tourist activity, and some great campgrounds. But, to go up there and then head to Boston will add around 100 miles to your trip.
There are things to do in the Albany area.
http://www.albany.org/things-to-do/attractions/Whatever you choose, you will enjoy either or both areas. Travel safe.