I would think your best best would be to rent a car if you have the time! Most car rental agencies allow you to pick up a car in one state and drop it off in another but you will have to pay a surcharge.
Load your suitcase into a regular NY taxi cab and have him and her give you a fast tour of midtown Manhattan, then drop you at LaGuardia Airport. Take the Shuttle(no reservations necessary) to Boston. Rent a car from there, tour Vermont and then return you rental car at Boston Airport. Less Headaches and complications this way.
Hire cars are easy peasy from LGA and the road system is good as well, I'd recommend getting your car from there. Do not drive in Boston it is the most terrifying place I've ever had the misfortune of driving on!
What do you mean this isn't how they eat onboard?
Queen Elizabeth 2 - Trans-Atlantic 2001
Queen Mary 2 - Caribbean - 2004
Queen Mary 2 - Mediterranean - 2004