The Montreal Canadiens have resolved the matter of their number one goaltender, and it's no surprise to anyone that Samuel Montembeault is the organization's trusted man, and rightfully so.
It's worth adding that when the Canadiens play two games on consecutive nights in different cities, the goaltender designated for the next day is already at the other destination, waiting for his teammates. In those cases, Jake Allen is the goaltender for the first game or the backup, but he might not be if the team had a day off between the two games.
In short, Cayden Primeau is the number 2 goaltender, and Jake Allen is the 3rd, that's very clear.