They are extending landing deadline. I reached out to them through web form and received a reply today.
Your confirmation of permanent residence document was valid to XX May 2010 as it was tied to the results of your medical examination. Based on your email below indicating you are unable to travel on or before the expiry date on your previously issued Confirmation of Permanent Resident document (COPR) and visa they have now been canceled, please do not attempt to travel on those documents as they are no longer valid. A medical extension will be requested on your behalf, should a new medical examination be required, you will be contacted. There is no action required at this time from you, you will be contacted in due course.
Reach out to them if you cannot travel.