For what it's worth, starting out from Northport, we made a stop at Fishers Island (West Harbor), where we anchored out. Really nice stop over... not much here, but we like it that way. Tie up at the dinghy dock, walk into town... a couple of nice places to grab a bite, etc.
From Fishers, we headed to Newport, RI... stayed at Goat Island Marina across from Newport. Again, lots of options; moorings, anchorage, etc.
From Newport, we headed up to the canal. As others have said, definitely watch the tides and wind direction... buzzards bay gets nasty!
We anchored behind the breakwater by Hog Island waiting for the change in tide to go through the canal... trip through the canal was actually pretty straight forward, especially at night (substantially less recreational boat traffic) We spent the night at the Sandwich marina, at the east end of the canal. We got there just shy of midnight...
The following morning, we watched as a sailboat floated past heading west on the canal, sideways! Again, watch the tides!
We waited for the change and did the trip across to Provincetown harbor and radioed Flyer's for a mooring. Launch service to town and back...
View from Pilgrim Monument

Enjoy!
Carlos & Maria
S/V Rocinante