The very suggestion of Canada being able to defend itself without the United States is a laughable one. It's so patently ridiculous it's hard to tell if you're serious.
The strategic adversary their fighters are likely to encounter, Russia, flies propeller-driven subsonic bombers for the most part. Any modern fighter is adequate to the task.
(it's beyond the scope of the current conversation but Canada's more pressing problem is having enough pilots and getting them enough flight hours)
Well, they need to do something. Kind of silly to ask them to ask the US to defend them against the US. It might be a cakewalk, but at least they’ll have tried to stand up to a wanna-be dictator, which is more than we’re doing.
You have nothing to win by thinking "as soon as they want to invade us, we will just give up, so let's just be an easy target"