@Bet01 - Hmmm, my friend rents out an AirBnB in the Catskills at Hunter Mountain. It will be beautiful as the leaves change colour in the Fall. It’s very quiet in the evenings there, tbh. It is where a lot of people of Ukrainian heritage take their vacations/weekends and own properties up there.
If you have no look with Enterprise at Fort Lee for a one way rental (or from a car rental depot in Manhatten) my suggestion would therefore be to actually rent a car from Newark Liberty International Airport (EWR) as most airport locations offer one-way drops.
I did a dummy booking for Enterprise and they definitely allow EWR-BOS rentals. Also if you are travelling with a spouse/partner and collect the car together they waive the daily $15 additional driver fee. I have no idea if other car rental companies do this but I know that Avis charges 20 pounds per day for an additional driver at LHR!
The www.newarkairport.com website will show you the various options of getting from Manhattan to EWR. I used to live over there and as three of you are travelling with baggage, I would definitely consider taking a car service to the airport, otherwise go to Penn Station in Midtown and take a train or even go to the Port Authority bus station just west of Times Square and take a bus.
However, if you choose a car service, they pick you up at your hotel and unlike the NYC Yellow cabs (which can’t pick up a return fare from NJ) the car services constantly go to and from the area airports. If you see guys with a sheet of paper with someone’s name at the international or domestic arrivals halls they’re usually from a car service. It’s a fixed fare plus toll for the Holland Tunnel…..plus tip (15% to 20%).
Car services include www.Carmellimo.com and Dial7 - or you could try Uber or Lyft to get to the airport.
Now, if you do choose to go to EWR, alight at Teminal B or C, (B is the nearest) and go inside the terminal and take the Airtrain (Monorail) free of charge to the Airtrain stop P3 which is where the car rental depots are located. The ones at EWR are:
Alamo
Avis
Enterprise
Hertz
National
Hope this helps!
Btw; Cape Cod is lovely too! You could even go whale watching :)