Sorry I’m not on your cruise because it is a lovely one! You didn’t mention the ship or itinerary but ours, years ago, went down the Saguenay fjord in Quebec early-mid October and we fell in love with that area and returned by land. It’s the end of the whaling season but we did see a whale off Boston and the St Lawrence has the largest variety of whales in the world though we didn’t see any from the cruise ship but have seen Minke and beluga closer to the shore later than your trip.
With the current climates around the world, I won’t put bets on the weather but if I were to lay odds, take layers for both warm and cool. You may get some warm sunny days where a light sweater is enough but if you get up at dawn to see a magnificent sunrise as we did one morning, a crushable puffy down jacket was blessing… so cold! Quebec City on our 13th of October was a gorgeous warm day but by evening we felt the temperature drop. Enjoy!
