You're expanding on why they haven't nuked Kiev or any other part of Ukraine. That all makes sense. I assumed that already in my argument and went for the next - they're not using nukes and they're engaing in a hot war mostly on Ukranian but also on Russian territory. Therefore having nukes doesn't guarantee you won't get a hot war on your land. You're not addressing that bit. I'm not saying you must, I just think there's a reasonable argument that a hot war under certain intensity on your territoty is possible even if you have nukes. Even if less likey than without having nukes. That's not an argument against getting nukes for Canada.
To speculate a bit, because of many of the same reasons you stated for why Russia hasn't nuked Ukraine, I don't think Russia would have nuked Ukraine, even in a fantastical scenario where Ukraine started the war with incursion into Russia.
Agreed on the points of Canadian defence.