I would personally wait until the rave to roll. The XX is phenomenal whether you're intoxicated or sober, and you can never tell what the mood of a crowd is going to be. I've almost always enjoyed myself and my peers at raves or edm shows both while sober and rolling because most attendees at these types of shows are there for the whole general experience--not just the music. With other genres, however, I have encountered quite a few individuals in crowds that I am not at all fond of.
My point is, there's going to be a much higher risk of your roll getting "ruined" at the XX concert (in my opinion at least). Whereas at the rave, more people will be in the same mindset as you and you're more likely to have a good time. AND your roll will be even better because you won't have burned up so much fuel the weekend before.