Cat
Ok, I'll answer your question; we could used conventional gliders at the following closed down VGS:
RAF Honington - plenty of real estate there and nearby good 'ole Uncle Sam doesn't fly that much at weekends.
Dalton Barracks (former RAF Abingdon) - plenty of grass as well as 2 runways at ~90 degrees to each other
RAF Halton - plenty of room and the GSA winch launch to well above 1,000ft on most weekends.
RAF Henlow - plenty of room from 3 grass runways.
RAF Odiham - the RAFGSA's Kestrel Gliding Club manages quite nicely at this site.
RMB Chivenor - no other users now that SAR has gone, plenty of room.
RAF Cosford - the RAFGSA's Wrekin Gliding Club manages quite nicely at this site, although it does have a UAS/AEF operating at the same time.
MOD St Athan - plenty of room if using the grass and leaving the tarmac for UAS/AEF.
RAF Topcliffe - plenty of real estate for gliding.
Swansea Airport - the first one where this might not be possible.
RAF Linton-on-Ouse - plenty of room on the grass.
RMB Arbroath - they have been comventionally gliding there for years!!!
Kinloss Barracks (former RAF Kinloss) - there is even a main runway and a parallel taxyway runway to choose from and plenty of grass.
Newtownards - the second one that would be an issue.
So Cat, I note that conventional gliding would only not be possible at Swansea and Newtonards. For Wales I would suggest setting up K21 VGS at Llewen Parc, Talgarth or Rhigos Gliding Sites. For Northern Ireland then Bellarina is about the only choice, or seeing if there is a GA airfield happy to have gliding.
Make sense?
LJ