Panshanger was my first thought too. Checking on google earth I think confirms that it was there.
You can see the outline of the big hangar and to the southeast is the low building, still extant, with the 'half octagon' two-story tower, visible as an outline.
I think the photo was taken from 51°47'59"N 000°09'09"W (hello.player.sound on what3words) looking approx 240T.
I see that 'Hopscotch' was released in October, 1980. I was quite active in and out of Panshanger then in various types, including Chipmunks, but don't remember any filming going on. Maybe the actual filming was done in 1979?