My mistake...we sailed Canada twice on Seabourn.
This will be our first on Navigator but have sailed Mariner/Alaska, Voyager/TransAtlantic, and Explorer/Caribbean.
Sept 2015 - 10 nights on Seabourn Quest, Montreal/Boston: Loved it! We were too early for the colors but have been to New England many times on land trips so that was not an issue. We were lucky enough to overnight in Quebec City which worked out as the first day it poured cats and dogs. The second day was sunny and lovely. We missed Prince Edward Island due to weather and we had really looked forward to PEI oysters. All in all, had a great cruise.
Oct/Nov 2019 - 12 nights Seabourn Quest, Montreal/Miami: I can't recall the colors. Seeing the colors is hit or miss depending on weather pattern. We won't be booking Seabourn again and we have over 120 nights sailing with them. Itinerary was fine but the service seemed as if Seabourn had really gone downhill. This was pre-Covid and we experienced lack of staff, sub-par service, running out of foods, very bland food, etc. Of course, this is after having sailed two cruises with Regent so we were comparing the outstanding service and amenities of Regent.
(Prince Edward Island was cancelled on this cruise as well, but it's not Seabourn's fault)
I'm sure you'll have a glorious time on Grandeur!