I know that Normandy Farms in Foxboro has a storage lot. It's a nice resort type park with public transit close by that can get you to Boston.
The place I store mine (Major's RV) is on the Cape, which is a little far from Boston, but once again there's a bus that goes to Boston from a 1/2 mile away.
Jerry & Jeanne
1996 Safari Sahara 3530 - 'White Tiger'
CAT 3126/Allison 6 speed/Magnum Chassis
2014 Equinox AWD / Blue Ox