How long can a person live with end-stage cirrhosis?

My Grandfather has lost all muscle tone (skin droops off his arms), has turned yellow, very thin and his speech is now a whisper. He eats very little, and he usually throws it up every 3-4 days. He sleeps alot, is very teary when my Grandmother leaves him, and is quite confused with the time and the day. He can no longer walk. How long do you think he has at this stage of cirrhosis?