Some roads were severely damaged. There is no way that the damage will be repaired in a week on some. There are likely alternative routes but the damage to the immediate area of the show was significant. Rivers in the area are still cresting. If you are planning on going to the show (I am) keep an eye on their website and perhaps even give the show a call before starting out.
The show promoters have announced that the show is still on and they recommend this route to get to the show due to the flooding and damage - Rte 422 East to 743 North and then left on Hershey Park Drive.
Rt 39 is fine to show, Rt 322 is fine to show & Rt 743 is fine, so from north & west access is great, trailers are all lined up and ready to see, don't worry about parking & access all are totally available and not too far 200 yards max, from gate.
2008 F350 Dually, Lariat, 4X4, CC
2014 Sierra 376BHOK
Wife, son & 2 Brittany Spaniels