Geography puts us in a bind. When it comes to software or any nontangible product sellable online like apps for example, we can sell those worldwide. But as soon as we throw transportation costs into the mixt, the US is our most beneficial trading partner due to population and proximity (all other factors being equal). that said, all things aren't equal right now. The US doesn't want to trade with us. Now had Trump picked a trade war with Canada only, we would have found ourselves in a tough spot. The good news is, Trump wasn't that smart. he picked a trade war with Canada, the EU, Mexico, China, and others I'm sure. So now the US faces multi-front retaliation. This puts more pressure on the US to smarten up.
That said, though the US is and will remain our most important trading partner, we should never sign an exclusive bilateral trade deal with the US ever again. Any future trade deal should be an open agreement allowing either partner to trade with any other state we want to trade with. So no more country-of-origin provisions for example. No US trade agreement with Canada should restrict Canada's freedom to trade with other states too, and the same should apply in reverse too.
I disagree. That will just aggravate the situation. Instead, they should not retaliate and Canadians and Mexicans should just boycott the US at the grassroots. The EU and China should join in this. No legal retaliation, just people freely choosing to boycott the US.