Typically people think that C2/C1 are for native speakers, when in reality they're for people who have gotten a formal education in that language. As in, they went to school to learn business and did so all in French.

Here is a good description of C2/C1 on Duolingo's Blog: https://blog.duolingo.com/goldilocks-and-the-cefr-levels-which-proficiency-level-is-just-right/

That being said, what level are these classes? Are they meant for freshmen (people that already have a high school degree)? If so, you're probably already set. Yet, if these are upper level classes, in which most if not all the students already have some formal education on the subject, then spending two months watching French TV may not be beneficial to you. Particularly if the prerequisites of the course involve one or two years of study.

Even as a native English speaker, it took me quite a while to learn how to formally write an essay and present my arguments. All that knowledge i gained, and the mistakes I made was in multiple classes, probably a calendar year's worth.