He's out of a job and he might have to live with his daughter...two pretty bad things to deal with, but the dream of Jack gives him pleasure, even with all the stuff going on in his life.
He might have to stay with his married daughter until he picks up another job, yet he is suffused with a sense of pleasure because Jack Twist was in his dream.
I think AP meant to show that his dreams of Jack were the only things Ennis had to look forward to...as Sara said, if he concentrates on it too hard, it might slip away from him...but he goes through his normal routine: pours his coffee, blows on it, doesn't "force his attention on it" and is able remember a part of it...a panel...that much didn't slip away. He can go back in time to that "old, cold time on the mountain when they owned the world and nothing seemed wrong."
Again, I agree with Sara...even the second to the last paragraph shows that it didn't matter if the dream was joyous or sorrowful...at least he had the memories, the remnants of dreams of that best time of all in his life.
"And he would wake sometimes in grief, sometimes with the old sense of joy and release; the pillow sometimes wet, sometimes the sheets."
