Consider Route 4 West from Portsmouth, NH towards Concorde. Pick up Route 9, follow through NH and Vermont (in Concorde, you will only be a few miles from New Hampshire Motor Speedway, depending on schedule, you may be able to take in some motorcycle activities there) to Route 7 in New York.
Follow 7 towards Troy - consult a map for youre preferred route to Route 20 leading out of Albany. (Short side trip to Saratoga to the auto museum in the state park??)
Take Rout 20 west past Syracuse (north edge of Finger Lakes Wine Country) and pick an interesting looking route north to Rochester. Quite interesting route, fairly straight with many very nice small communities along the way. Downside is some areas between Albany and Utica could have heavy truck traffic going to and from a couple of I90 interchanges. Interesting nearby side trips include Cooperstown and Watkins Glen (track of course plus Interational Motorsports Library)
Alternate: consult some history sites and follow the Erie Canal