Depends on 1 year (course based) or 2 year(thesis) based.
If you are doing course based...it doesn't matter except marks since you'll most likely to paying tuition on your own.
Thesis-Master's, your supervisor may be able to provide more funding if you are Pr/Cdn citizen as the tuition cost is lower. Thus, some supervisor may only have the funds for a domestic student. However, you still must meet the gpa cut-off.
At Queen's ECE, you're guaranteed minimum 19900 stipend for each year for domestic, the international student gets ~26k to offset the increase in tuition. So if a prof was looking for a student and you happen to have the same marks as an international, you'll most likely be taken due to lower costs.