I wrote that I could as easily live in the US as Canada (or some other places like Germany, Britain, France, etc), which is not the same thing as wanting further integration with them or wanting to move to any of those places right now. I do want people to put more energy into preserving the integration we already have rather than crying "all is lost" and putting energy into burning it all down as fast as they can because they got butt-hurt over something insulting Trump said about Canada, or because they're sinophiles or pro-EU or have some other agenda.
Raising the spectre of provoking separatism in Canada and wondering who might want to separate or worse isn't a path with only one pitfall. "Vive le Quebec libre!" is part of our history, too.
We shouldn't be dealing with China to any greater extent than we deal with Russia. They are predatory states. "Russia out of Ukraine. China out of Tibet." Trump's US is a predatory state; but there is all the difference in the world with the qualifier "Trump's", and the magnitude simply isn't the same. We obviously shouldn't be simultaneously dealing with China because it has bullied us into compliance and then standing up on our hind legs to bark about not being bullied into compliance.