I went to a very small college, and I roomed with a friend from my very large high school. Neither of us had any problem making new friends, both together and by ourselves. In case you want a more recent example, most of D’s friends went to UMich. They didn’t room together in the dorm, but two of her good friends rented a house off campus with new & old friends. The young women are now very happily married to two of the new friends they met in the rental house.
There’s nothing wrong with going to school where your friends are going to school.