tell your HR now.
make the changes on Canada Post. l think you can let the know the effective date ahead of time.
You have to notify your bank, service Ontario (on line) to change your address on OHIP, drivers licence etc.)
https://www.ontario.ca/page/change-my-address-ontario-services?gclid=Cj0KCQiAy9msBhD0ARIsANbk0A_8NWZtaRerJhH9JAXRkcrgZ9IjmmngZbyKK6A176ieThWNzpuk-NkaAv7kEALw_wcB&gclsrc=aw.ds