The now elderly pair of 747-200’s that serve as the basis for Air Force One have had the same refrigerators for their entire 30 years.
Despite constant servicing to the highest levels, the elderly 1980’s refrigerators which have to store food for up to 6000 meals (in the event of protracted national emergency with all appropriate persons and crew on board), are no longer capable of functioning – never mind that the refrigeration gas they use is now no longer manufactured.
The US Air Force has awarded Boeing the contract to install new bespoke refrigerators in both aircraft, as they have to function for at least another 5 years, probably longer, until the next pair are finished based on 748i’s.
The point to be made is that for example on a protracted overseas trip like the one taken by the current President to the Middle East in 2017 for nearly 13 days, ALL of the food is stored aboard the aircraft and nothing is sourced from destination airports.
In many cases both aircraft fly – one empty as a backup or with extra press. If you look in the background to the Presidents arrival at Ben Gurion last year, there are a couple of brief shots were AF1 is taxiing to position while the other aircraft is in the distance parked up about a mile away.