CaptainSwanFan asked: If Hiccup or Astrid died, how would the other cope?

Well, if you read "Worth Fighting For", even in the five minutes Astrid was dead Hiccup was pretty distraught. So, if Astrid really truly died forever, Hiccup would be miserable. He wouldn't wanna really do anything, and even Toothless' wouldn't be able to cheer him up. I'm guessing that eventually Hiccup would be so consumed with grief that he'd.....well.....DIE. And Astrid....she would probably be the same way. That's my guess.