The reality in Winnipeg is that, when they arrive, most people expect to be integrated into an anglophone community. Without giving the issue too much thought, they enrol their children in the school closest to them, which, statistically speaking, will probably be an anglophone institution.
However, I would like to add that, in the immersion courses I teach—especially in high school, where some students drop out because they are not given the paraprofessional support they need—my students make up a very mixed group compared with what I saw at the beginning of my career. Today, I see many children from immigrant families, like my own. A number of students come from Asia, Africa and Latin America.
I am picturing my current ninth-grade classroom, a third of which is made up of foreign students. Their family comes from abroad. Those people have chosen immersion and are among the biggest believers in the system's effectiveness. Moreover, since they already speak two languages at home, adding a third one makes perfect sense to them.