(But keep the flying advice coming.)
Our oldest cat, Fritz, is doing very poorly, so Finn and I are not traveling at all, and Pete will be leaving Sunday instead. (Many thanks to the airlines for the 1800 + 300 they wanted to charge us on top of our 1200 in order to change our flights to Saturday. It makes perfect sense to me, really it does.)
We will take him to the vet at 2:30, and realistically, I don't expect him to return home with us. He's 20; I doubt there is much they can do for him at this point.