Where you are resident does matter for income tax, and the Canada Revenue Agency looks at your residency status for the tax year in which the sale closes, not at the province or country you happen to be in on possession day itself.
A lawyer regulated by the Law Society of Saskatchewan can close the sale on your behalf under a power of attorney if you have already relocated, so leaving before closing does not require you to delay the sale or return in person.
If a move is already planned, coordinating the closing date around it, rather than around the calendar, is usually the more useful question to solve first. Get your hand-reviewed valuation from Joel Dyck.