Hello!
I spoke to UWO about the GRE and was told they wouldn't look at the GRE scores, but I am Canadian so not sure if that would apply to you. The contact person I had was; Janet Harman (jharman3@uwo.ca). I've come to discover that institutions that require specific prereqs have shorter programs, unlike schools that don't, like Dalhousie for example which has none, but the program is 3 years.
You don't need French to practice in any the other provinces, with the exception of Quebec, New Brunswick (the only bilingual province) and Nunavut (there is a considerable French population). French is fairly easy to pick up, and it might be something to consider as your placements at McGill will be done in both English and French environment(s).
Good Luck!!!