I have recently landed in Canada (end of December 2018) and I am now waiting to receive my PR card.
I am wondering if I can go abroad for couple of weeks without having PR Card. Prior receiving my confirmation of permanent resident, I was on work permit and I got a multiple entry visa which expires in 2020.
Can I use my multiple visa to come back to Canada?
Answer is no given now you are a PR any permits/visas issued before becoming a PR are no longer valid.
There is a chance the system still being updated but you could possibly end up getting stuck outside of the country with having to apply for a PRTD or entering via the US /Canada land border with your COPR assuming you have a US visa. Decision is yours if you want to take the risk of being denied boarding