David's plan to have Jules and the kids hide in Canada makes no sense. Fleeing to a foreign country would potentially protect one from domestic law enforcement, but not from the international criminal organization hunting them which clearly has the resources to track down, and kill, people in multiple countries. If David wanted Jules to fall off the radar then it would be better to stay in the US where they would not have to risk a border crossing. The safest thing to do would be to send them to the US authorities who would put them beyond the reach of any criminal reprisal.