Every time I read a government advisement that says "stock up on medications" I make one of those "yeah, right" snorty sounds.
You can't just "stock up" on medications. More and more pharmacists will not give give any more than the prescription dictates and they won't even let you overlap a new prescription until the old one is (by definition) complete.
Doctors really don't have much to say about it.
The best you can do if your prescription is going to run out while you're traveling is to find a pharmacy close to where you'll be staying and have your prescription filled there.
I just asked my doctor if he would write me a script for a 60 or 90 day supply in case of emergency in addition to my regular script, and he said no problem. I filled it at Walmart, and paid cash.
Took the other script to my regular pharmacy. No problem. The insurance company dictates that script shall not be filled until you are down to your last 3 pills from the last fill date.
Sometimes, I put one pill back in a spare bottle each month too.