I can offer some insight, since I went to Canada for a semester. I actually got in a bit of a kerfuffle with my exchange coordinator because I only got 6 ECTS per four credit course - my faculty expected me to do 5 courses. However, almost all of the other exchange students, including those from the same university as mine, got 7.5 ECTS per course so they could do four courses and be done with it. In the end, I also did four courses, totaling 16 credits and taking home 24 ECTS. They were 400 and 500 courses (third and fourth year courses), essentially the most advanced level of undergraduate courses there. Got straight As on three of them. Fourth was a group effort, so a B- IIRC. I think I could've done a fifth course or five easier courses plus lots of parties, but that is not why I went to Canada.