There really are not that many RAF airfields left in England that could host this, apart from EGDL - decent runway + loads of aircraft parking - and as for the earlier suggestion "draft personnel in from elsewhere"...
There are barely 30000 of us now and few aircraft. BBMF and RAFAT will surely be appearing near most of the population next year - I think that's plenty to keep the service in the public eye.
Who cares if Waddington doesn't host another? Since it became the ISTAR hub the place is far too sensitive to let 1000's of unknowns roam about the place anyway.