20 Unanswered Questions From 2017's Comic Book Movies

6. Why Will The Mutants Suddenly Be Safe In Canada? - Logan

The Question: Why will Laura and the other mutant children suddenly be safe if they can cross the border into Canada?

The Likely Answer: Though it's ultimately just an invisible line and Alkali-Transigen could feasibly venture into Canada to hunt the kids down, the implication seems to be that it would most likely spark an international incident.

The mutants get granted Canadian asylum over the radio, and the suggestion is that the Canadian authorities would likely meet them at the border, putting up a fight against any insurgent forces if necessary.

Again, that doesn't mean Alkali-Transigen wouldn't send assassins out to catch the kids later on, but at least in the immediate aftermath of their escape, they're safe.