Upvote:3
You'll be fine, you don't even need an extension. Canadian visa expiry dates signify the last date on which you can seek admission into Canada. They do not dictate until when can you stay.
The expiry date on the TRV is the date by which the visa must be used to seek admission into Canada. If the visa is not used on or before that date, it ceases to be valid.
The validity date is NOT the suggested duration of the visit. At the port of entry examination, CBSA officers determine the length of time temporary residents are authorized to stay in Canada.
Source: Government of Canada