If they deny your PRTD, you will either need to wait to return until your PR card is processed (assuming all goes well) or return through a land boarder with the US.
If the PRTD is denied, it automatically starts the revocation of PR status, subject to appeal. The PR card being renewed will NOT counteract this.
This is an important clarification.
For emphasis: if a PR TD application is denied, that will result in the loss of PR status UNLESS there is an appeal and the appeal is successful. Even if IRCC issues a new PR card that will NOT save the person's PR status.
I phrase a small part of this a little differently because
the decision to deny a PR TD is the official decision which terminates PR status. My perspective is that saying it "starts" the revocation process can be too easily misunderstood. That decision terminates PR status unless it is appealed and the appeal is successful. Once the decision to deny a PR TD has been made and the affected person properly sent notice of that decision, IRCC does not need to take any further action at all to effect the termination of PR status (that is, termination of status will
automatically take effect once the period of time to make an appeal has passed,
unless the affected person timely makes an appeal).
SUMMARY: Once a PR TD is denied, PR status can be saved ONLY if the PR takes affirmative action to make an appeal, and then wins the appeal.