I always bring a hoodie or jacket on the plane with me and wear pants when flying even when it's warm (it's air-conditioned in airports and planes) so I have pads and warmth when needed. It's often looped through my backpack arm strap. Also earplugs and noise canceling headphones/earbuds. My backpack has a nice pad in the back. He'd have been infinitely more comfortable if he had any of these things. And hell a book or something.

With the armrests you can kinda double wedge yourself on them. I got 2 decent hours in the lima airport doing this. They had the similar double seat with no armrest setup.

I got to ORD at 4am for a 7am flight and purposfully fell asleep on the ground in front of the check in desk figuring they'd wake me up. Eventually they did. The attendant woke me up and said "do you happen to be on this flight". I pointed at the first class ticket hanging out of my shirt pocket. "Good thing I checked we're closing the door now". I was like "I figured you'd maybe wake up the person in front of the desk I've been up for 38 hours." "oh you were sleeping I didn't want to bother you".

The entire flight had boarded and just walked around me. I was OUT.

Le Sigh.

I slept "overnight" (02:00 - 04:30) in the new Berlin (BER) airport a couple of years ago. Not only are the concourses completely closed to passengers overnight, but the floor in the check-in area (the only area that is open) is made of terrazzo. Your hoodie and pants would make essentially no difference on this surface. Certainly not if you were 60 years old :)