Get a refund.
The website is showing the state of the parking areas and the airfield grassed areas. There is no way that they will safely take 100,000 people with their cars / trucks. It would be horrendous for the authorities to deal with the recoveries of vehicles. The organizers had not choice and if Joe Spotter complains cos he hasn't been able to see an aeroplane, unlucky, think of others..
The real shame is the damage to the RAFCTE coffers, but public safety does come first.