Hi Steve @steveny9, I have small fiber PN but haven't taken any long international flights. I did take a long day flight from Minneapolis to Nome, Alaska. I tried to get up often to stretch and move around a little. I did have an aisle seat which helped a lot. The only downside for me was traveling with a teenage nephew sitting by the window and getting up every 10 minutes of the flight to move around 🙂. Since that flight I've learned that compression socks help. Now I have to wear them daily since being diagnosed with lymphedema in my legs. Here's an article I found on the topic that might be helpful.

"For longer flights, those with neuropathy need to be able to maneuver comfortably. Sitting in the same position for long periods may worsen symptoms. Since air pressure inside an airplane cabin may cause swelling in the feet, patients should wear compression socks during the flight."
-- How to Manage Neuropathy Symptoms While Traveling: https://fapnewstoday.com/columns/travel-planes-symptoms/.

@artscaping and @denrah may also have some suggestions to share with you for going on long flights with small fiber neuropathy.