Canada has the longer runway because:

• better social safety nets and not federally leveraged to the hilt
• Canadian allies willing to lend both short-term financial aid and long-term mutually beneficial economic partnerships, vs U.S. former allies that will absolutely respond to them as we are doing (I think this is the realization that has Dumpster running scared; he's finally figured out the biggest economy in the world is still no match for the entire Commonwealth + EU)
• national unity vs escalating unrest -- practically every U.S. move is strengthening our unity and dividing the states further
• the volume of private industry being harmed stateside is way more powerful than the U.S. civil infrastructure, whereas I'm not sure which side is bigger here but the difference in relative sizes isn't even comparable -- plus plenty of our private business has chosen solidarity anyway
• more stateside jobs vulnerable to supply disruption than Canadian jobs in the supply chain (possibly even per capita, but definitely in absolute numbers)
• public perception: to some extent, we can outlast the U.S. as long as we think we can (this is the factor that's hard to maintain and a big reason why some things would only be said in private)

What Canadians would be afraid to hear probably sits somewhere in the ballpark of promising he's ready to gamble countless Canadian jobs and security on the position already taken. Some form of politely but firmly and explicitly challenging Dumpster to his face -- calling his bluff. Other possibilities include sharing threats/promises on how the government has prepared* to respond further in some scenario. Basically some strong counterthreat that probably isn't a bluff.

*privately, to avoid panic, internationally-seen escalation/harming Canada's image, or fueling propaganda for anti-Canadian sentiment