One option could be to ride south towards Albany, NY, then somewhere between Saratoga and Albany, head east across southern Vermont and New Hampshire, into Maine.
It's been many, many moons, but I did a tour from NYC to Montreal. North of Albany we stuck to the roads along the west side of Lake Champlain and Lake George, mostly 9 or 9N, whichever was closer to the water at the time. We did another tour from Albany to Acadia. Not sure how we got out of NY, but I believe we rode routes 9 and 202 across VT and NH, to route 1, then up the Maine coast. Both tours, back then, were very nice, with plenty of small towns and ample places to stay.