Once your permanent residence is approved and you have your eCOPR, a Temporary Resident Visa (TRV) you obtained earlier — even if it's still technically valid on paper — can no longer be used to enter Canada, since becoming a PR effectively supersedes and cancels prior temporary-resident travel documents.
What to use instead: for land border crossings, your eCOPR together with a valid passport is the correct document combination to re-enter Canada as a new permanent resident, before your physical PR card has arrived. A Permanent Resident Travel Document (PRTD) is a different document needed specifically when you're abroad without status proof and need to fly back — it's not what you need for a land crossing where you already hold your eCOPR.
If you're unsure which situation applies to you (land crossing with eCOPR vs. flying back without status documents), confirm with IRCC or a border services officer before traveling, since using the wrong document at the border can cause delays or complications.