Thank you, JDiver, for sharing this so openly and generously. Your post is a great resource.
My mom passed away from Alzheimer's this past July. She started traveling later in life and truly enjoyed it. Three years ago, we took her on one last trip to Philadelphia to visit family. She was early stage 4 at the time, and it required a lot of the thought and planning that you detail. Her gait was pretty slow so we got wheelchair service in the airport. Everyone, from TSA to the flight attendants, were very kind and helpful. The trip and visiting family meant so much to her that the logistical challenges were more than worth it.
Kudos to you for your efforts in facilitating this source of joy for you and your wife as long as possible. And I echo jspira's offer - please feel free to pm me if you ever want to chat.