I think you'll find that that hangarage, along with the associated dispersals, has been rather heavily repurposed by the two resident Regiments!
Not the VGS stuff. The lovely new hangars that were built the last time Chivenor was reopened have been taken over by the logistics Regt as has the 22 Sqn Hangar and dispersal.
The important vehicles are all in a purpose built environmentally controlled building.
There is plenty of space for an AEF.