I am in the same boat, my application was received on the 14 march 2018 and sent to the London office July 6th. the GCkey account hasn't updated anything since it still says application in progress.
From what I understand, the next step is to get a per-arrival letter (confirming the relationship is valid)
Then its the background check, if that completes then we get a decision made letter and request to send the passport copies to a visa office.
once that is done. The next request is to send the passport to the Islamabad office where it gets the visa. Then I can book my wife a ticket to come to Canada