If you return to Canada before your current PR Card expires, you should be fine.
If you are returning to Canada after your card expires and you have not yet received your new PR Card, you’ll have to apply for a Permanent Resident Travel Document (PRTD). You’ll need to bring all the documentation you can showing that you have been travelling abroad for a Canadian company in order to safely apply for that PRTD. Even then, it’s a risk. Return before your PR Card expires if you can.