Thanks, everyone. I thought something might be a bit off with that long a connection time advised. Actually, the rest of the referenced web site is filled with very comprehensive and useful information that is reinforced by other sites I've visited. (I have no affiliation with the web site in any way.) Who knows? Maybe just one bad experience led the moderator to his connection information. In any case, I now feel relatively comfortable with my itinerary barring a late departure of my DL flight. If that happens, we'll just have to count on a day in Athens before heading to Santorini - not the worst thing to have to face.

PS. Thanks also for moving this to the appropriate place, moderator.