If I were you and was put in a twin room, I'd wait for the other person to move out - then you get a giant room with 2 beds that you can put together to make a double bed! That's what happened to my bf and it's awesome!
Alternatively, you might end up with someone you really like - happened to two of my best friends, they are sharing a room and now they're so so close and are living together next year!
But if you really don't like the twin room thing, you will be at the top of the list for reallocation (excluding those who have to live off campus!). So don't worry - you'll be in there for about 5 weeks at most.