I'm from Monmouth County and heading that way on Friday. We go GSP all the way to the top. We're going to Lake George first so will continue up I-87 (Ny thruway). When we go to Boston we either take, from top of GSP, I287 to I-684 or go up NY Thruway and connect to I-84 that way. On GSP north of the Driscoll Bridge there are a few low stone overpasses that are fine if you move one lane to the inside. We've gone this route 5 times with no issues.
Randy & Sharon & Ella (terrier mix rescue)
2013 Tiffin Phaeton 40QBH
2014 Ford Edge