If you mean Canada's travel ban, that travel ban didn't apply to PR Card holders returning to Canada so that's not going to fly (pardon the pun) as an excuse, sorry to say. The ban applied to tourists and, in some circumstances, workers and students with permits.
Now, if you're talking about driving that is a slightly different story - as the border is "closed" to non-essential travel - but if you showed up at the border with your PR Card (which proves you live in Canada) then I don't think they would have denied you entry. (Unless, of course, they realized you could not possibly meet the residency requirement. I don't know what your days outside of Canada amount to.)
You have three choices at this point if you cannot return to Canada before your card expires:
- Apply for a PRTD and hope that they give you one even though your card has expired, because they understand that the pandemic has screwed up international travel for anyone.
- You can travel to the United States and attempt to enter Canada by car with your COPR. Normally this would likely work (unless they find out you cannot meet the residence requirement). However, during the pandemic I don't know if a COPR will be good enough for entry. Someone else asked this question on the forum, but I never heard what they did.
- Renounce your PR and apply for PR again - this is a super extreme option and should only be contemplated if you do not currently meet the residency requirement.
Hope this helps.