I thought the same, MayflowerMadam. But then I thought...whichever one would travel (Trump, or Melania/Barron), they’re going to have to go through at least one and maybe two airport locations. I know they wouldn’t go through the actual terminals, but would still be in the vicinity. And with demonstrations in the streets in DC and outside Trump Tower, they probably figured it would be safest for all concerned to stay put.
The Presidents wife and son would travel on Air Force jets.
No airports involved except military ones.