I believe this poll is accurate for the period during which the participants were canvassed.  When push comes to shove, these numbers may well shift.

A cynic might say now that: 

(a) if the Federal Government decides at some stage to accede to some of the US's harsher demands because they conclude, on balance, this is the best they can achieve on behalf of Canada, then Canadian public opinion will be angry with the Federal Liberals, but

(b) if the US begins a trade war by being unreasonable, then many Canadians will argue that our Government should somehow have avoided the impasse that led to this.

Our Government will need to show resolve and leadership and be prepared to take difficult decisions and we as citizens need to avoid undercutting Canada's negotiating position by acting during these negotiations as the cynic would predict. We all need to rise to the occasion, put to one side our domestic partisan political concerns and stand calmly together concerning the negotiations.