I know that many people belive that Janner comes back to life after TWatWK and have good reasons to.
But I disagree.
I belive that the sacrifice for un-transforming the Fangs and the Cloven is somebodys death and therefore Janner dies and stays dead.
And many say that the story whould be to sad if Janner stays dead but I also disagree with that, too.
Janner is now safe, with the Maker and his father, Esben.
So, really, the ending isn't all that sad at all.
I'm quite satisfied with it.
I'm iffy on both sides. I will say that I think Andrew Peterson ends the story so as to let the reader decide what happens.