There’s a discussion on Pprune that started a few months ago and I think the consensus was not as well as Duxford – but as Duxford was particularly suitable, where could?

Personally I suspect Sywell is the only place near enough to possibly make the show viable. There were all sorts of suggestions thrown out but given the running costs of WW2 fighters and similar, and the availability and logistics of enough pilots for the show, I can’t see anywhere further afield would have any chance of making financial sense.