There isn't a definitive answer to this question. It is best left up to individual reader opinion; therefore, feel free to pick what you believe and defend it. I think it is a perfectly viable answer to say that Jonas dies at the end of the novel. The beginning of chapter 23 tells readers that Jonas feels that he has little hope of actually reaching Elsewhere. Then is starts to snow and the temperatures drop. We get a some narration about how Jonas is so freezing cold that his legs feel "leaden" and he can barely move. Then he miraculously begins to feel happy and joyous, and his memory is flooded with images of his family and friends. It's very much like his life is passing before his eyes which is a very common thing to say about death and/or near death experiences. He could absolutely be hallucinating as a side effect of hypothermia. Personally, I think Jonas dies of hypothermia. That's sad, but I don't think it diminishes his efforts. Jonas is willing to try. He's willing to try and break free from the Sameness. He is willing to see that there is a problem with his society, and he is willing to do something about it. He happens to die, but that doesn't make his efforts any less heroic.