As you say, Waddington relied on student accommodation in Lincoln, therefore it seems reasonable to assume that similar arrangements could apply with Finningley (ie- Doncaster or Sheffield). Naturally there are logistical issues, but in principle there's really no reason why Finningley couldn't be used as a show site. As ever, it's really down to will and motivation. One assumes that nobody has any interest in creating a civilian-run event even with RAF support. Likewise, Waddington's organisers seem to be interested only in the future of Waddington's show (if it has one).