You can apply RRP (Returning Resident Permit) from any embassy of Canada. With a valid reason such as expatriation by an Canadian company, finishing study, etc, any reason they judge justified. Normally this kind of visa will be issued for 1 yr or 2 yr long. For me leaving from Singapore, I applied only 3month (already approved) for the reasons that I need to sell house, clear tax, cancel residenceship in Singapore, etc. Good Luck to you, buddy.