Hi cokezero,
Below pasted is a paragraph from CIC website:
[size=10pt]Confirmation of Permanent Residence[/size]
" If your application is approved, the visa office will issue a permanent resident visa to you. Your permanent resident visa includes your Confirmation of Permanent Residence and your entry visa. Your Confirmation of Permanent Residence will include identification information, your photograph, as well as an expiry date by which you and your dependents must arrive in Canada. Please check the information on your Confirmation of Permanent Residence to make sure it is correct. It should be the same as the information on your passport. If there is a mistake on your Confirmation of Permanent Residence, contact your visa office.
You must have your Confirmation of Permanent Residence and your visa with you when you arrive in Canada."
From the above what do I understand is that the COPR expiry date is not indicating the PR Expiry.The PR expiry date will be given on your PR Card.
Regarding entry to USA by road with a copy of COPR and your passport could be possible if the BSA officer allowes.
What I was hoping was that in case i don't fullfil the PR residence requirements (ie expires in 2013), I can still be let in to Canada (if i wish) as a PR since my COPR doesnt expire until late 2014.
I don't think you can take the COPR expiry date into consideration. Probably you may have to get another expert opinion.