In Canada, network interruptions are pretty streamlined similar to the United Kingdom. Master control facilities for the major networks are hubbed in a central location (primarily Toronto), and if a interruption were to occur it would transpire with a simple preemption notice or a jump cut to a live studio.
Unfortunately, network interruptions are a rare occurrence. They directly result into lost advertisement time, the primary source of revenue for most stations. The closest "special report" you'll get in Canada is when it's planned ahead of time.
It's worth noting that in addition to hubbed master control that (I believe) most of the networks supply the full programming day - save for local news. When they carry and transmit the full schedule live there's little need for a countdown or a large coordinated effort. Additionally most networks are made up of owned stations with each having less than five affiliates which clear most of the schedule and has little need for the dramatic cut in.
It should be thankful that special reports occur so rare in Canada where in the US it's usually means something bad has happened. But given this current presidential administration political special reports are more common and not in a good way.