@YYT123 Have you looked at Tasis in Lugano? It is much better academically and has Canadian students. You would get to be in Switzerland ( Italian speaking region) and still have exposure to true diversity ( many people from many places, though mainly all very very wealthy). They have the same types of travel trips that might be drawing you to Le Rosey but are more geared to education if you plan to return to North America as well as study in Europe.
You didn’t mention what year you are in. Many of these schools start very early (6th grade) and go through high school. You should also check out other schools.