It all depends on the CBSA agent. Others have been sent back. It is quite a long time to visit family especially when you are not planning on going to school in the city. There is more of a chance that students will work illegally from doing childcare to other jobs.
I think you are fine with just the letter from your brother saying he will cover all your exspenses plus a letter from his employer, his previous bank statements, and any savings you have. I entered last June for my Student Visa and CBSA didnt blink an eye
