What is a good reason to visit Canada in November?
For the skiing!
Probably the best reason is that it's off-season for most places, so air fares will be lower. It'll be a good time to visit family and friends in Canada because the Christmas rush will not yet have started and unless you like winter sports, it's not a time to go for an activity holiday. Many parts of Canada that get really cold in the winter will not yet be colder than a domestic freezer.
It is kind of miserable right now where I am, just east of the Rocky Mountains, but it will probably get nice again, and permanent snow might not come till the end of October. Maybe even some time in December. It didn't snow till Christmas Eve a few years back.
There is this absolutely beautiful in between season, where it isn't truly winter, but autumn has fled. Life has hushed, but it can be sunny and nice.
It is something that a lot of tourists do not get to experience.