One more option would be to see if her Doctor would write the prescription for more per day than normal, this would be after explaining the problem with traveling.
I have what is referred to as Failed Back Syndrome from having back surgery in 2005 that did not turn out very well and I understand your problem. My Doctor writes my script for 90 days at a time but after that I must pick up a new script at her office. Also, at my Walgreen's if someone else besides me is going to pick up my order I must notify them before hand.
When it come to hitting the road I need to be very aware of my prescription renewal time and either have to plan to be back in time to renew or plan ahead to have someone setup to do it for me. Unfortunately now a days with all of these pill mills and people selling their prescriptions this is what pain sufferers must deal with.
I hope that you can get it figured out.