I've just been given access to the notes of the Chairman of the Green at Ringway Golf Club in 1949/50. They invited Braid to return to the course (he'd previously made alterations to the original Colt course when further land became available). The two of them walked the course. One of the club members had suggested putting a bunker in a particular spot. Braid's response was,' No, the minimum width a fairway should be is 20 yards and anything less is not fair to the golfer.'
Seems narrow enough to me!