Following the news of my friend with a COPR issued after 18th March 2020 and a written authorization from IRCC, he successfully landed last night without any problems. Here is a brief of his situation.
FSW outland from Iran, received his PPR email on 12th March 2020, but COPR was not issued until December 2020. He requested authorization to enter Canada since his brother is a Canadian citizen and received approval after 2.5 months. Requested authorization before he received his COPR
He had his tickets booked and asked for ok-to-board 5 days in advance and got one from Qatar Airways airline. He had every documents printed and carried them with him, and successfully landed last night
@_Hotshot