Just received my COPR one day before the interview. Lucky me.
Timeline:
Dec 1st: Received email from CIC to join the pilot express landing program
Dec 3rd: Replied to confirm availability and information
Dec 7th: IRCC sent my COPR through regular mail from Montreal
Dec 12th(today): Received the mail with 2 copies of COPR and an instruction letter.
Dec 13th: Scheduled phone interview date
So it looks like that it takes about 3 to 4 days for Canada Post to deliver your COPR. I am hoping all the other guys that have their interview scheduled tomorrow have received their COPR already!
BTW: I live in Vancouver