FlyerTalk Evangelist
Join Date: Nov 2018
Location: Istanbul, Turkey
Programs: TK Elite Plus,BAEC GGL,ITA Executive, AFKL Gold,QR Gold,HH Diamond,Bonvoy Gold,ALL Gold
Posts: 14,186
The first option would be OK but in case of a delay in the Delta flight, you would lose your rights for the domestic flight. In addition, the wait at passport control for non-EU citizens could be long during peak season, especially when the flights from USA and Canada arrive all at the same time. Otherwise, the transfer is doable but the risk is not worth it if you are traveling with children. A walk-in ticket for a domestic flight in Greece could be up to €300-350+ per person during the summer.