Which city is better to live in for expats: Calgary or Winnipeg?

It depends on what you can do.  Calgary is a pretty dynamic city, but it goes boom, and bust with oil.  And, that is the main industry there.  Winnipeg has a much more general economy, and does not really have the same cycles.  One can make more money in Calgary if you are lucky, but then again, it is easier to become unemployed there.  Winnipeg has a somewhat colder climate.  Both cities have people from all over world, so it does not really matter what country you come from.