Since there are 2 dates available, I would wait. That is what we are doing. We will be there for the 12th & 14th. We'd prefer to go the 12th, but if the weather is really bad that day, then we will try for the 14th. We are hoping that there isn't a sell out before then.
You can still get the advanced ticket price by purchasing the tickets at your resort (if staying onsite) the day of the event.