So I'll be going to a predrinks party tomorrow to a flat full of students from my University. Around 60 people will be there, the ambient will be club-like; low lights, loud music and afterwards we will be going to a club. Since its a predrink the atmosphere will be focused more on talking rather than dancing as in the club.

If I meet a girl I like, should I escalate and go for the kiss at the predrinks or chat her up and then escalate in the club?

If I do not escalate at the predrinks the issue I see is that I would have to chat with her at the predrinks, break contact (since we can't chat for two hours straight lol), and then re-initiate in the club.