So....both of us have passed the "3 score years and ten" and we've finally nailed this international travel thing. When you book airline tickets use the "need assistance" button. you will be picked up at the ticket counter, wheeled thru TSA and taken to the gate or the plane and given priority boarding. If travelling international you are picked up at the Jetway and wheeled thru immigration and baggage claim and thru customs . It works a treat and the only charge is a tip for the attendant. Some of these airports are set up for marathon runners and are beyond the scope of elderly passengers.
On one trip we landed in Munich at Gate 2 and our connecting flight was at gate 88 in 40 minutes. Not possible without wheeled transport!!