I spoke to one of the operators of Solent Summit (the long US N Gauge layout) this evening, he is a member of our club.
They were having a problem with the Digitrax throttles working on WiFi as all of the WiFi hotspts at the NEC was overloaded, so they were having problems controlling the layout.
Even so, I think they put on a good show. I have seen this layout on a number of occasions (in a smaller guise) and this has not been a problem at all in the past.
It was a really big problem apparently, Layouts using Marklin Z21 control had similar problems as they also use public WiFi frequency.
Something to bear in mind if you intend to exhibit at Warley using WiFi throttles.