A visa is a travel document and is not required if you are not travelling to Canada. So
- If you are currently in Canad and do not plan on leaving Canada between March 2017 and when your study permit expires, you do not need to renew your passport at the moment. If you renew your study permit for December 2017, or get a work permit, and plan to leave and return to Canada, you will only need to renew your visa then.
- If you are in Canada but plan to leave Canada and return to Canada between March 2017 and December 2017, then you will need to apply for a new visa only a few months before March 2017, when it expires.
- If you are planning on leaving Canada before March 2017 and returning after March 2017, you should apply for the new visa either a few months before it expires or when you returning to Canada.