Just finished a re-read and the ending still hits me. The man dies, after fighting for so long. It’s quiet, not dramatic—just his body giving out in the cold. The boy stays with him for three days, then a man with a woman and two children appears. They’ve been tracking them, and the man says he’s one of the 'good guys.'
The boy is hesitant, rightfully so, but he eventually goes with them. The last pages are the woman telling him she’s glad he’s with them, that they won’t ever eat people, and that she talks to God in her prayers. The final image is of trout in a stream, 'in the deep glens where they lived,' a memory of a world that’s gone.
It’s not a happy ending, but it’s not utterly hopeless. The boy finds a new, fragile form of community. Whether they’ll survive is left open, but the 'fire' is passed on, I guess.