When I stayed in the Million Dollar Falls campground in Yukon territory (between Haines and Haines Junction), I was in bear country. I saw one bear (my guess grizzly) the day before I arrived and two days after I saw two black bears. I crossed the US/Canada border and the guards gave me mixed messages when they asked if I had bear spray with me. On the one hand, bear spray is controlled at the border and they knew I wasn't bringing it into the country. On the other hand, they way they asked questions suggested I might be foolish to cycle in that area without bear spray.
From memory about a decade ago, Canadian bear spray had a legal spiciness limit that some US bear sprays breached, making them a weapon Up North. So it would be one of those things that would get checked entering Canada but less of an issue going the other way. And yes, I didn’t camp etc up that way without bear spray.
On pannier related issues, I can’t believe you’ve 5 pages into this thread and no one has mentioned Carradice waxed canvas panniers. Easy to repair and reproof, and you can leave them in your will to your grandchildren as long as they don’t get eaten by rodents in your shed.