Go to the Music Major Forum - there are a number of threads about this. Check out some of the pinned threads at the top. Note that Sophie Shao is a cello professor at both Bard Conservatory and Vassar. https://music.vassar.edu/bios/soshao.html
Of your list, for non conservatory programs, Swarthmore, Vassar and Wesleyan have the strongest classical music programs and student musicians. You should add Williams to your list - drop Amherst. And if you want Ivies with strong music students and ensembles look to Princeton and Yale.