One thing to think about: My understanding (which I am not quite sure of) is that universities in Canada will care a lot more about your most recent two years. For the most famous Canadian universities (Toronto, McGill, UBC) a GPA of 3.2 is most likely too low. However, there are quite a few other very good universities in Canada.
Also, the uptrend might help you at universities in the US.
It is possible that university admissions in the US might already know what grades are needed in your country to be in the top 30%. More specifically, they will probably have someone on their admissions staff who knows. Assuming that you can afford to study in the USA (or Canada) you might need to just apply and see what happens.