In the past when I've told my pharmacy I'm traveling somewhere with less medical facilities than the US, they can get a refill sooner from my insurance provider

In the past when I've told my pharmacy I'm traveling somewhere with less medical facilities than the US, they can get a refill sooner from my insurance provider than I'd otherwise be good for. That said, it doesn't work for all drugs. One of the medications I'm on now I can't get filled one day early under any circumstance, nor can I get it shipped to me. For extra fun points, if I'm late by more than a week, it's doubtful I can get it refilled ever again.