Glad you had a great time Kuger and didn't let the film limit you.
Sometimes what I'll do if I'm facing slowish shutter speeds in dim halls is use this to your advantage.
Try 1/15th or below and get the dance motion happening.
Sometimes it works, sometimes not but worth experimenting with.
I know you said you had no flash but you can get some cool stuff also if you use second curtain sync and use slooow speeds.