The processing for PRTD, depending on which counties you are applying? In my case, it took only 5 days to get PRTD.
Assuming you are form visa-exempt countries? If so, you can return to Canada with your passport without apply for PRTD, keep in mind, do not tell an airline that you are a permanent resident, if you tell them that, they might not let you boarding or you can travel to the US then drive a car through US-CANADA border.
Note that, new entry requirement is Electronic Travel Authorization (eTA). Now delay Until September 29, 2016 so you don't need it too.
Enjoy your vacation