If you're still looking for a home base for your RV, definitely check out Stow Minuteman (6B6). It's about the same distance from Cambridge as Lawrence, has a great restaurant and the cheapest avgas in the area, and is a nice airport community to boot. Access from Cambridge is relatively easy on Route 2. The owner/manager is a friend of mine and I'd be glad to put you in touch with him if you shoot me a PM with your contact info.
Run, don't walk, from Hanscom (KBED). It's operated by Massport and they seem to do everything in their power to drive small GA from the airfield. Plus, you'll pay big-FBO prices for gas.
There are lots of RVs at ASH and PYM if you're willing to drive further. I'm based at ASH and can tell you more if you'd like, and there are other folks on VAF who are based at PYM.
Good luck with your move!
Nashua, NH (KASH)
Putting the "slow" in slow-build since 2004!