How does the story end? Do Jonas and Gabriel make it to the place called Elsewhere or do they die attempting to do so?

In the novel's conclusion, Jonas finds the sled at the top of the hill and sleds down the hill with Gabriel, heading toward a place that he knows will be Elsewhere. Finally, he forces his eyes open and sees Christmas lights in front of him. He hears music and singing for the first time, and he even thinks he hears it from behind him in the place he left, although this might only be an echo. They made it to Elsewhere.