one could do DTW-YYZ in J for a total of 30xp RT. Add one domestic connection on each end (4x round trip) and your itinerary could total 54xp in one RT.
One could do that (or LGA/JFK-YUL/YYZ) but that would require at least 5 days of one's life flying around on Delta, at a higher price than I paid with just a click from the comfort of my office.