2 thoughts: there are a few meds that can only be prescribed a month at a time. Sometimes that is a federal mandate (drug schedules). Insurance companies have also been known to impose that stricture, the cheap poopyheads. IME neither will budge if that is the case.
Depending on the med, the doctor might be willing to write a separate prescription for you to not run through your insurance and instead pay out of pocket to get past it if it is a problem caused by insurance.
2nd thought: pharmacists have many wondrous ways to work around this type of travel blockade, ways that aren’t known to us mere civilians. Go to your local pharmacist, lay it out to them and ask what can be done. Sometimes it is as simple as them transferring your prescription to pharmacy where you will be when your current supply runs out. They have other ways as well.
The last thing they want you to do is “walk” your meds, skipping days to build up a supply. As a cranky old, grizzled night nurse I don’t want you to do that either. That is always a bad idea and with some meds a really really bad idea.
Please go talk to your pharmacist. If yours isn’t local, establish a relationship with one who is and transfer your prescriptions there, at least for the duration of your travel.
If the solution ends up being you paying for prescriptions out of pocket, use GoodRx to minimize the cost.