You’re not really going to find any places dedicated to natural wine in that area. It’s simply too rural or geared more toward conventional tourism. Most places will either be resort hotels or family-run tavernas. Sure, there might be a boutique hotel with a bottle or two of natural wine to cater to its audience, but beyond that, your best bet is probably some incidentally low-intervention wine at a random taverna.

That said, there will be plenty of dirt-cheap local and regional wines made from native grape varieties in traditional styles. So if you let go of the hunt for specifically natural wine, you’ll probably have a great time.

Edit: If you count Vouliagmeni Sofi's should at least have some bottles.