I don't have access to a chart at the moment - a look at streetmap shows Upwood to the north west of warboys.
I'm thinking of Warboys the pathfinder field where there was a nasty accident with a Victor in the 70's. The town of Warboys is right next door. A search on the BGA site shows nothing.
There were perhaps 8 gliders drawn up on the SW facing runway as if to be winched off, there were cars parked nearby, but no people were obvious.