I am in a similar condition. My visa is already expired on 3rd of march. My work permit will expire on 3rd of May. I called up cic. She said I should apply before my work permit expires. I am waiting for my PPR. If I do not get before end of april, I will apply for work permit extension... Expiry date for Visa is okie as long as you are not travelling out of country. Check with them if you are travelling out of country...