It's interesting for me reading all of this. My university life and holidays were much as you are mostly describing - I came home during holidays, caught up with friends from school and work, partied, etc.
DD's life is very different. She went to boarding school at 14 so her friends are scattered around the state, and she has a few from much further afield.
They stay in touch online very effectively, and when she's home she takes my car and visits them, or they visit us, or they get together to see films or go bowling or just go to the mall. She doesn't drink when she's out, and partying isn't really something she's interested in. I don't think she's been to a nightclub in her life - her socialising is all done on campus or at friends' houses.
Her life is so different to mine - I'm not sure how 'normal' it is for an American college student either.