Earlier quoted context omitted.
I wouldn't color relying on a historical ally that either produces, or is the transit corridor for, most of your food with "everything to lose". The current trade spat is an issue, and Canada should react accordingly, but the reality is that, even with tariffs, the US still represents a very profitable trade partner, especially when they can levy tariffs of their own.
If it was just the trade spat, you might be right. But there's also Trump repeatedly talking about annexing Canada. That goes well beyond a trade spat, and I would absolutely expect Canada to do more in response because that is in the mix. Including actively working to reduce their dependency on US-sourced or US-transiting products.
At the very least you would expect them to start looking at other sources for arms.