The US Ambassador to Canada is openly threatening Carney right now with some procurement things - the 'Big One' is the F35.
This is Can PM Carney playing a decent card, and biding for time until the midterms, and then waiting out the 'lame duck' period.
'Border State Republicans' are badly upset with the anti-Canada situation, and will buck Trump if given the chance without massive repercussions.
Trump may not force the issue if he knows he's going to lose.
If we see Trump with conciliatory language towards Canada after the elections, it's because he knows he's been beat. Or if he just shuts up about it and let's the negotiations roll.
I give it 50/50.
But - to be very clear - the world is 'doing 1 nudge' away from the US - not 'breaking away'.