It would likely be whenever Telus or Bell put up towers there that support Koodo phones. I have no idea when that might be. My understanding is the local provider has an agreement with Rogers so I don't see them signing with Telus as well. Sorry. (Just to note I have no employment with any mobile phone company so I have no inside information).
Give it time, it's only a few months since koodo was even able to offer HSPA service in Thunder Bay. I believe the next phase will be covering the trans-canada highway up to the Manitoba border. Beyond that is anyone's guess.