Go by yourself! I went to the midnight showing by myself. It was great and even though I had to go to work the next day on 3 hours of sleep, it was well worth it!
I went again last night with DH- because of course, he couldn't go alone.
I felt weird the first time I went to a movie alone, but once the movie starts, you can't talk to the person you went with anyway.
Go see the move.....you will LOVE it. And I agree with Yarnlady- those Weasly twins