I think the PC's have (2) cards to play:
1. Get out ahead of "ending the lockdown" and campaign on the wrongness of having isolated and locked down the entire population to protect a very small vulnerable minority, and all the damage that caused.
2. Promote a "New Environmentalism" that focuses on real progress Canadians can see and feel. No more money for CO2 as long as China is belching the stuff out at rates that make Canada look trivial in comparison. Let's make a difference. Expand the national parks. Expanded the protected marine environments. Move money from buying CO2 credits to cleaning up our lakes and rivers. No more "Ecoli"-days closing our beaches. Large reforestation programs. Grants to municipalities to "green up" city parks and schoolyards. In particular, provide large numbers of maple trees all across the country. Then to show our global good will, out money into ocean clean up and sponsoring wildlife protection areas for threatened species. The PC's need Canadians to realize that spending billions of dollars on an invisible gas that is primarily plant food is silly when there are so many other more pressing issues.
Well, that would be my "swing for the fences" shot at it anyway.....