If you're planning to spend the winter in the same area, find a doctor there for your yearly appts. Or, if you return to your previous home area, stay with your doctor there for your once a year appt. They can write prescriptions of a year.
While you're traveling and become sick go to a quick medical clinic for minor ailments and a prescription for it. If it's an emergency, go to an emergency room.
It is all very doable no matter where you're at. I even went to a wonderful clinic in Canada for a gall bladder attack. I received excellent service and the doc even call a couple times later to see how I was doing. It was a very reasonable fee - $65.
When you do have a prescription we have always used WalMarts to fill them. Then as we travel they are easily refilled. Others use Walgreens or mail order, etc.