Okay, so from what I can ascertain.
The Agreement in Principle, AIP, is set on american terms. But the AIP is unenforceable until clause 5 is hammered out. Until clause 5 is hammered out, clause 4 is in effect, the original deal.
So when the bridge opens, Canada collects the tolls and it everything proceeds as normal, except the net revenues sit in a holding account, waiting on resolution of clause 5. (Canada could spend it, but if the americans have their way they would need to refund it)
So Carney, being a banker, is probably going to foot drag this until after the mid terms, and create a economic dependancy that is harder for trump to just shut down.
Optically, its a win for Trump. Functionally, it depends who wins the long game and Carney is betting he can outlast Trump here.