In the Maritimes there are plenty of places to haul and store a boat.
Starting with one in the Gaspe and 3 or 4 places in the Bay of Chaleur.
Another large facility on Ile Madame in the strait of Canso (Cape Breton) and also a few smaller yards in Baddeck in the Bras dor Lake. In Nova Scotia
there is East River Marine
(new) and also South Shore Marine
The best place of all is Lewisport in Newfoundland
Get a copy of Yachtpilot's "Down East Circle Route" guide which covers the trip you are planning--St Lawrence to Maine
. It will give you a list of places with the phone
numbers etc. Then for Newfoundland
and Cape Breton get their Cruising Guide to the Canadian Maritimes.
There is easily enough to see and do in Atlantic Canada for 2 seasons