The Canadian Social Insurance Number (SIN) is used, among others, by the Canadian Pensions Plan (CPP). My social insurance number is a temporary one, as I am a temporary resident of Canada (work permit). But I believe I should have a relation with the Canadian pensions plan for the rest of my life. Considering that the CPP administrates pensions by SIN, what happens to my relation with the CPP after my SIN expires?
The money still belongs to you, regardless of your work status. If your work permit expires, you can continue to contribute or withdraw your funds but since you cannot work, your employer cannot direct-deposit anything to your RRSP account.
Your choices are: if you expect to get a new work permit, you can keep your funds in Canada, or if you're expecting to leave permanently, you can withdraw them and take them with you.