I travelled NZ to London, while on treatment. Most importantly, mask up. I used a travel mesh nebuliser - cheap online, and I actually prefer that to my plug in. I took my saline in vials and bought supplies while there, online.
Take letters from your hospital or pulmonologist and prescriptions. Keep all medications in their original containers.
Oh and be aware your chest can feel like it's going to explode when you are coming in to land, if you have lungs that are hyperinflated.
Enjoy travelling again!