Just let me clarify again..
Once Ottawa office done with stamping on your passport, you will see an update on your CIC account stating "Your Application is Approved". There will be no COPR letter comes within CIC online account. Once application got approved, within 4-5 days return tracker get activated and you will receive the passport along with COPR in another 1-2 days. Once you get your COPR then you need to do the landing and once you do the landing you can't leave the country until you receive your PR card.
If you have a COPR and if you haven't done the landing yet then you can go on a trip outside of Canada; carry your passport and COPR letter along with you and while returning to Canada, do your landing. This will be an option. But safer side, you can ask/verify with couple of other people prior to this.