Hi Tandan, (and hi Bleu!)
If you already have your ticket, we suggest arriving right at 10 PM to get some dancing in before Act One starts at 10:30... That way you have a chance of making it through till at least the Battle at the end of Act Three - its a marathon...The four hours from 10:30 to 2:30 are definately the peak of the night..
Stevie Method go-go begins at 9:30, if you want to come even earlier - believe me, the room should be full by then with some twirling space left..