Excellent, welcome backRob_TO said:So we arrived back in Canada yesterday... and just to confirm for anyone else in same situation there was zero issues with not having the actual PR card while travelling.
In Cancun airport the check-in person at Westjet asked if my fiancee (Korean passport) lived in Canada. She said "yes" (since we do), so she asked to see PR card. I just stated she's travelling as a tourist, and passport is visa-exempt... and that was good enough and no more questions asked.
Arriving in Canada, the immigration officer easily took the COPR as proof (even though it states "not valid for travel"), and just matched up the landing date on COPR with stamp in passport from Canada on landing date. No issues or delay at all.
Just for people who see this in the future: The CoPR isn't valid for travel but it is proof of status once you are at the border itself.