I totally do my makeup at my seat on a long flight if I can’t get off the plane looking like a mess.
First off - take your makeup off before the flight/off the plane so you can take your time & space and have normal air to do it in. Get on the plane with a clean, well moisturized face like you’re ready for bed.
Then right before you land: I use micellar water wipes in the bathroom to take my face off, and put on moisturizer and tinted sunscreen while in there. And then my makeup - which is fairly simple, but enough so I look ok - under eye corrector/eyeshadow/mascara/tinted lip balm - I do at my seat once the moisturizer sinks in. Maybe I get weird looks, but I don’t mind, and it also distracts me from being impatient waiting for the plane to land.
My full skincare routine (serums, actives, etc) can skip that morning, or really, what tends to happen is I do it mid-day-ish when I get to wherever I am going or have more time.