I was surprised to see that, within a year of the Treaty of Versailles being signed, anyone had the will to organise Olympic Games, let alone in Antwerp which had fallen (after a siege) as early as October '14 and was occupied for the duration. At least in 1948 London had three years to recover from war and had never been occupied.
I'm sure Genghis has the right idea about the casual way "they" would have just gone and flown over if someone had had the idea.