Canada's efforts should be on preparing for the NAFTA negotiations in concert with Mexico (including lobbying House and Senate members, industry representatives and State representatives that represent US interests and jurisdictions that have a large stake in trade with Canada and Mexico).  

Canada is the market for about 18% of US exports and Mexico for about 11%. The benefit of these exports is concentrated in several States and industries of importance economically and politically. Such lobbying to mobilize early support will have a breaking effect on the capacity of Trump to pursue rapacious goals in a bullying manner.

US trade partners generally are, like Canada, eager to find alternative trade relationships and markets to lessen their reliance on the US.  Seriously exploring (and being seen to be exploring) greater 3rd country possibilities now while preparing to renegotiate NAFTA promises to both lessen our reliance on US trade and strengthen our hand in NAFTA negotiations.