Plot hole

I've lived in small towns all over. Canada's small towns are no different from any other small town. Hell, I lived in a town of just under 1000 in upstate Michigan, so I had the one stoplight and the giant piles of snow experience too.

One thing you're forgetting -- or never knew -- about small towns is that isolation produces a need for communication and information, and that means more radios than you'd expect, especially in an environment where the weather can damage or take out hardlines and break up the coherency of television signals a lot more easily than radio because of the greater complexity of information being conveyed (i.e. you lose a TV signal more easily because TV signals have a lot more information that can be degraded.)

In any event, your argument is fundamentally flawed for an entirely different reason. A pretty obvious one, at that. People in the region (and the "Beacon on the Region" call emphasizes that it's not just restricted to a couple square kilometers here) and outside the region (via relays) can't get information from sources that have no information to give. This radio station is located right in the middle of the events, so it has a greater insight into what's happening. Information spreading to bigger radio stations and TV? The entire BBC sequence made it clear that the information that these other places had was second- or third-hand. That's why BBC, a multinational conglomerate with resources this Pontypool radio station could only dream of, contacted Mazzy to verify their story. A story they were getting completely wrong and flailing wildly at, incidentally. All by himself, Grant knew more than the entire BBC network. They didn't know jack and were looking for someone who did. That was the entire point of the scene. In this case, it was the only people broadcasting from Ground Zero. That's the point you're missing. Grant and co. were broadcasting because there was nobody else in the area who could. It seems almost fatuous to suggest people tune into, say, the CBC when the CBC had no more idea what was going on than some random TV station in Paraguay. Their source of information? The radio station actually in Pontypool that was familiar with the residents, the area, and the guy in a Dodge Dart looking down at the scene.

Remember how Sidney kept saying that there was nothing on the wire? That was the movie making -- pretty explicitly -- the point that there was no 3rd party information. All they, and the rest of the world, had to go on was that one radio station's sources, which included a radio station employee on a hill, local cops Sidney knew personally, and random townspeople who hadn't yet fallen victim to the virus but were still hysterical with fear at what they were seeing. Oh, and a doctor that crawled on his hands and knees across a snow-covered landscape to talk to them in person. And with Laurel-Ann's death, they provided the only first-person account of someone going crazy from the effects of the virus.