Revivng this question to tell you all that Fright Nights and halloween in general has essentially become the new summer, queues will be ridiculously high (I waited half an hour on the ride access queue for Hyperia, which probably had a 300 minute normal queue wait last year) and crowds will be absolutely packed. Alton Towers' scarefest also has the same issue and not even Chessington or LEGOLAND are safe from the long queues too, especially at half term. Simply put, if you're going to a major UK theme park this halloween, be prepared for the worst.