Hello I also got dm Jan 8 and no ppr my work permit is going to exp Jan 24 so I have already apply for a new one. I know that you can apply till the last day that your work permit is valid in your case February 16 but i think is good to do it lets say a week before the expiration date so if you get the ppr you can always withdraw the application as soon as you do the landing.. also when i asked the agent told me that they don't advise me to do the border crossing for the landing without a valid work permit althow that i am in the implied status and that it will be better to book an appointment for the landing in the office..