My husband and I looked into what had happened and talked about it and decided that in our case, it wasn't really worth it. He makes enough at his job that we didn't need to then, and we figured that by the time a second work permit was actually processed and I got it, even if the PR process had taken the full year I would only have had the work permit for a couple months before it became invalid because of PR. And with the way it turned out I'm glad we didn't, because I probably would have gotten the work permit right before I got PR, and it would have been a waste of money. I did get some benefit from the work permit, in that I was able to get a temporary SIN, I was able to apply for and get MSP, and there was less worry about traveling outside of Canada than if I was just here on visitor status. We had made several trips across the border to the States, both by car and by plane, and I never had any trouble with re-entry into Canada. I have NEXUS, and they never questioned me about immigration status at all, only asked about our declarations.
I did get to keep the actual work permit document after my landing interview. The lady that processed me looked at it and did some things in her computer and then wrote VOID on it and gave it back to me.