It presently needs an update, but here are the county "fairs" in NS.

My favorite route to Atlantic Canada goes through Eastport, Me, to a ferry to Deer Island, NB. The ferry from Deer Island to the mainland (a bit south of St. John, NB) is part of the roadsystem, so it's free. Best time of all if no school calendar intervenes is the week after Labor Day. The weather's still warm, things are still open, but the tourists have mostly gone away.