Canada has about a snowball's chance in hell of leaving FVEY, unless the United States is severely weakened. And I am talking about "Divided States of America" level of catastrophic failure. And that is assuming Canada did not break apart due to the amount of chaos it caused, nor did Canada ceases to exist before United States. It is often said that Mexico is "so far from God, so close to the United States". Guess what? The same thing could be said about Canada.I'd give Canada an outside chance of leaving. Mainly because of the Francophone seperatist element. But even they seem to be fully on board when it comes to China.
Canada of today is not Canada of the past; it has practically no independent foreign policy. And its international clout is a shadow of its former self, as seen by the hilariously pathetic attempt at lobbying for a UNSC seat a few years ago. Hell, even as recent as 2003, Chretien could at least tell Dubya to take a hike when it comes to Iraq. Nowadays? Well, lol.
While the Dominion of Canada's entire raison d'être was "how do we organize ourselves to NOT become the United States of America", I would say it has been failing at that objective since 1867.
Aside: Quebecois seperatism here is a distraction and non sequitur. How much interaction would there be with hypothetical independent Quebec and China when it is on the Atlantic side. And what would China think about people randomly splitting country apart, especially considering MFA's previous statements about various secessionist movements around the world?
So no, even if FVEY magically disappears tomorrow, Canada cannot and will not deviate from United States in a major fashion when it comes to China unless United States implodes.