If you didn’t get back before the pandemic, you are probably going to have problems keeping your status.
Under normal circumstances the best thing to do in this situation is to fly to the States and have someone come down and pick you up and drive you into Canada. (You can enter Canada by private vehicle without a PR Card.) There is still some risk of your status being revoked in this situation.
But, honestly, we don’t know how the pandemic is going to affect Canadian PRs living outside of Canada who were not meeting the residence requirement. There’s probaly very little political will for an amnesty in this situation and so it’s definitely possible that there will be no official extension/waiver of the residence requirement in cases like yours.