What would Princess Leia wear to the prom?

I have a costume conundrum. It is one month (minus a day) before Geek Prom. I want to be Princess Leia going to the prom. No, I do not want to go in a Princess Leia costume. I have a pair of awesome buns (that I put on my head) which were made for me a couple years ago when I was a Princess Leia PEZ dispenser for Halloween ( And again was a PL PEZ at the Minnesota PEZ Convention and won third place in a costume contest).

But the PEZ costume is very difficult to move in. So difficult, in fact, that at a Halloween party a couple years ago I asked  Geek Prom founder to move my car out of a tight spot. This was a favor gone bad, as he was equally impaired by alcohol as I was mobility impaired; end result was a scratched car. Never let your friends drink & drive. Or drive in PEZ costumes.

Anyway, I don't want to be an imperfect replica of the movie  Star Wars Princess Leia and nor do I want to be a mobility impaired PEZ dispenser. I want to be  Leia going to the prom. I'm pretty sure they didn't have  proms a "Long time ago in a galaxy far, far away".

Or maybe the 80s, when I didn't go to the prom in high school, suffices as a long time ago, but now is the  galaxy where a girl with cinnamon rolls on her head goes to the prom.
 
Dress suggestions are welcomed.