Happy to answer any questions you have. I learned after doing research that the airport outside of Athens is a decommissioned airport. If you see an X at the end of the runway, it is not in use. The snow scene was in Metsovo, Greece. We went there for two nights and it snowed the second day. Each city I flew, I checked DJI Go app to make sure there weren't nearby airports or restricted zones. The only restricted zone I saw in Athens was the Panathenaic Stadium. As much as I really wanted to fly there (I've seen plenty of other drone shots there), I did not because there was a red perimeter around it so I didn't even try. The rest of the city I did not see any restrictions nor no drone signs. I also had absolutely no issues from anyone while flying.
In Santorini, there were a few No Drone signs in Oia where the hotels and residences were. It was low season so I figured there wouldn't be as many people to disturb so I did fly from Oia Castle (no signs) over the ocean and did not get close to anyone's residences. I also flew throughout the rest of the island where it was mostly scenic landscapes and not over major residences. I made sure not to be annoying or unsafe with my flights.
Everyone's experience my be different, so I encourage you to use your judgement wherever you go. There were always times and places where I scouted and felt like it wasn't a good place to fly, so I have so far avoided any and all conflicts, whether it was crowd related or weather.
