Sandy, I honestly don't know why I'm even giving any advice since you've made up your mind anyway.
Anyone, whether they have MG or not, can have their O2 tank on an airplane. It has to do with pressurization, air speed and, well, greed because they save money on fuel by manipulating those things. There are many articles on hypoxemia and pilots. Who cares about passengers.
When I went to Europe, I had an oximeter with me. I highly suggest you get one too, if you go. Sitting in a seat at 38,000 feet, my O2 was in the 80's. When I walked to go to the bathroom, it went down into the 70's and I had a "little" chest pain. The risk of a heart attack or stroke from a low O2 is very real. Have you had your heart and breathing assessed by experts (cardiologist and pulmonologist)? Did they do breathing tests in the hospital?
You can't only take the "ok" from your neurologist because you really need that from a pulmonologist. Why? They are the ones who assess breathing and can write a script for O2 on a plane. Neuros do NOT do that!!
I can understand someone newly diagnosed with MG thinking that they are now superwoman because they have a diagnosis, a doctor and drugs but the fact is that MG - contrary to what Dr. Franklin said - is not "mild." You can't tell by a stationary patient what MG will do to them once they are mobile.
It would be quite easy for you to go into a full blown MG crisis on a trip. No, I'm not being negative but realistic. Things are not "stable" for you yet. And, frankly, you haven't been on drugs long enough to know when that will happen.
So that's my typical newbie "lecture," sent with great kindness and concern. Do what you will with it.

Annie
I forgot something. Long distance travel like that, especially if you're on a steroid, can wreak havoc on the adrenals. Jet leg is simply your adrenals becoming confused because they don't know what time it is and if they should put you to sleep or not! It has to do with cortisol levels and the normal pattern of them being higher in the morning when you should be awake and lower at night when you should be sleeping. Travel to another time zone disturbs that normal balance.
The hardest adjustment would be while there and then on the way home. I had an adrenal "crash" so bad during the flight back and after I got home that I couldn't stay awake for ten days, had horrid sweats (another adrenal crisis symptom) and my muscles were much weaker. I got better but it was pretty horrendous. If you feel that way, you should ask your primary doctor to check your cortisol levels.
This can also happen when a patient is taken off of Pred too quickly (too much of a dose decrease). FYI.