First of all, they're not even usually called "redeye" when they're between continents. Overnight flights are the norm between continents (going eastbound or north/south). And, as such, since they're only flights in many cases, of course they're packed full in economy most of the time!

The "redeye" flights that you may be thinking of where people sometimes get 3 across are domestic "repositioning flights"; ie, the airline is running the flight not because there's high demand for it most days, but just to get the plane eastbound for use in the morning somewhere east. The 3 across then is due to the reason these "redeyes" exist (not because of the distance and/or the 6/7/8/9/10 hour time zone change, but because of a reason other than passenger demand).

But that scenario doesn't exist on longhaul international flights.

I'd say a slightly more practical goal, even though it doesn't get you to true horizontal, is to get an exit row seat (of which there are very few, and only people with status can reserve them ahead of time). In a good exit row seat (and yes, on these planes only some of the exit row seats are good!) you can recline much more because you have all that legroom to "slip down".

But gosh, you need hoitzontal? You don't even get truly horizotal in AA's business class seats! If you really need truly horizontal to sleep, I suggest you start planning for no sleep on these flights as a backup.


But do you realize that one of your flights is not even quite true overnight? The flight back from Hawaii is simply a late evening flight, in terms of Hawaii time. You may land when it's waking time in DFW, but it'll simply be very late in the evening to you if you're still on Hawaii time. So especially that one, you might want to plan to not sleep, and just sleep after you get back to DFW. (This is of course assuming DFW is your home airport, which you haven't explained whether it is or not.)