Not by much, US exports to Canada and Mexico total over 600 billion dollars. That's a lot of US jobs. I seriously doubt the US Congress would let Trump walk out on NAFTA. There is far too much at stake for all concerned, not just jobs but America creditably around the world.That depends on what you call overnight. From his 100 day action plan:Trump will not end NAFTA unilaterally or overnight.
FIRST, I will announce my intention to renegotiate NAFTA or withdraw from the deal under Article 2205. ★ SECOND, I will announce our withdrawal from the Trans-Pacific Partnership. ★ THIRD, I will direct the Secretary of the Treasury to label China a currency manipulator.
I think he will add to his plan; deal with the resulting financial crisis.
https://assets.donaldjtrump.com/_landings/contract/O-TRU-102316-Contractv02.pdf
Negotiation is not pretty. Canada and especially Mexico need the deal more than we do.
What people don't understand about trade treaties is all parties are winners, at least that is what they believe when they sign them. They take years to negotiate and are reviewed by thousands of people.