Traveling with PMR

I am thinking about taking a cross country trip, for the first time in six years. My close cousin is getting married.
Most days my PMR pain is still high, even on 6-8mg. of Methylprednisolone. It gets a little better as the day goes on, but most days I have to push myself.
I am trying to decide between flying, or taking the train in a roomette.
Can anybody weigh in on the pros and cons of these options?
I am worried about not enjoining the trip if I’m in pain, but I have already missed out on so much in life.
Kathy