IRCCC has (finally) provided some details as to the process by which PGWP holders can extend their status.
Take a careful read of the announcement on the IRCC website here. Some individuals don't need to do anything; a new work permit will be sent to their mailing address. Others, however, will need to apply and restore status (even if they are beyond the typical 90 day window).
Open work permits for individuals with expired or expiring post-graduation work permits
Foreign nationals whose post-graduation work permit expired or will expire from September 20, 2021, to December 31, 2022, will have the opportunity to work in Canada for an additional 18 months by either extending their work permit or applying for a new one. Those currently in Canada will also have the ability to work in the interim period while their permit is being extended or a new one is being issued.
These measures will affect individual applicants in different ways.
My post-graduation work permit expires from October 2, 2022, to December 31, 2022, my address is up to date, and my passport is valid through April 2024.
You don’t need to do anything. When you receive an email from IRCC to confirm your mailing address, don’t respond. An updated work permit will be sent to your mailing address by mid-October.
My post-graduation work permit expires from October 2, 2022, to December 31, 2022, but I need to update my address and/or passport validity.
When you receive an email from IRCC to confirm your mailing address, follow the instructions in the email to let us know that your mailing address needs to be updated.
If your passport validity doesn’t allow us to extend your work permit by 18 months, you will not receive this initial email, but you will receive a separate email in September.
If you need to update your mailing address or your passport information, you will receive instructions by email in September on how to update your mailing address and passport validity in your online account. You will get a 2-week window to do so. If you update this information, you will receive an updated work permit in the mail by mid-November.
To ensure you will be able to benefit, check your passport validity and apply to extend it if it expires before April 2, 2024. If you applied for your post-graduation work permit using a paper application, make sure you have linked your application to your online account.
My post-graduation work permit expires from October 2, 2022, to December 31, 2022, but I won’t be able to update my address or passport validity.
You will need to apply online to extend your work permit. You could receive a work permit extended to your passport expiration date or you could wait to apply until you have renewed your passport.
My post-graduation work permit expires from October 2, 2022, to December 31, 2022, but IRCC didn’t contact me.
If you do not receive an email from IRCC by mid-September, you are not eligible to have your work permit extended through this special process for another reason, such as information has been added to your file about your admissibility to Canada that will need further review. You may still apply online to extend your work permit.
My post-graduation work permit expired or will expire from September 20, 2021, to October 1, 2022.
You will need to apply online for a work permit. Applications open on August 2, 2022. If you are in Canada and your temporary status has also expired, you must apply to restore your status at the same time. Under these special measures, you are allowed to restore your status, even if it expired more than 90 days ago.
You are eligible to apply from abroad if you have left Canada and return after you have been approved.
Note: You may not apply for this work permit at a port of entry. All work permit applications for this public policy must be submitted online by December 31, 2022.