Hey there,
Memorial is a better place in terms of winter weather and that’s all. Winnipeg is a much bigger city and has way better jobs, better pnp and being a city it’s got the big city life. It is much bigger than St. John in all terms.
The only problem is the winter is frigid in Winnipeg. It touches -10 on an average. But Winnipeg is a way better city than St. John. Unless your budget conscious Manitoba is a better choice. Also the mba at Manitoba is more job oriented and gives specialised skills, the memorial program will give you a general MBA.
All the best