I will face the same problem when we start full timing next year. I see a pain management doctor every three months. He gives me a script for 30 days with 2 refills.
I have TFL and use express Scripts for all my mess except for the pain med which I get at a local Mom and pop pharmacy.
I've told my PM doctor about my plans to travel and as of now he said I would have to be seen periodically in order to continue to get controlled med (I take buprenorphrine) from him. I'm hoping he will agree to stretch it out to every 6 months. If not, I will fly home to see him as required and hope that I can get my buph from Express RX.
Funny thing is that I have two daughters who are both MD's but they can't risk the rath of the DEA to prescribe for me.
The abuse of prescription medications by recreational drug users has made it extremely difficult for those of us with chronic pain to get the mess we need.
In anticipation of this, I weaned myself off of my pain med but was so miserable that I know that is not feasible. So like you I'll manage the best I can.
I have an emergency stash that will last me about a month if I run into problems but since I've been seeing this doctor for several years and always passed my annual drug testing I'm pretty sure my plan will work.