Don't they ask questions about your personality and likes/dislikes and habits when you apply for housing so that they can fit you with someone who will be most compatible? I think they'll be happy to fit you with someone who doesn't drink. There are students out there who go to college and stay away from the party scene.... look at all of us here who did/do.
Another option is asking for a single room. I know you said that all rooms are doubles, but there is the chance that you could get a single... my brother has been in a dorm for 3 years and got a single each year. I also had a friend in college who had a single in a suite of 3 rooms, the 3 rooms shared a common bathroom and she happened to have the small room. So there is the chance that you may not have to room with someone, although what a great way to meet a new lifelong friend. I wish I would have had the courage to do the dorm life. Have a good time and good luck with all of this!
In memory of the sweetest german shepherd I ever had the pleasure of knowing. I love you, Duncan. 3/12/02 - 12/19/11