How do you decide if it is time to "make someone comfortable" after a stroke?

My grandfather is 87 years old and has a major stroke after a TIA 3 days ago.  He is paralyzed on his right side and has 100: blockage in his corated arteries.  Surgery will not be performed and his living will states he does not want any surgeries or feeding tubes.  He is responding to my voice and he can say "mmmhum" and "alright."  He is aware of his surroundings and who is speaking to him.  His left side of his face will smile when he finds humor so I know he is "in there."  His eyes opened today but will only stay open for a minute at most.  He is awake but with eyes closed.  I am his POA and have provided his living will to the doctors which states he does not want a feeding tube, etc.  They say we will wait 2 more days and see how he responds before we talk about "making him comfortable."  He currently only has an IV, no nutrients.  If I allow them to feed him nutrients through a tube through his nose will this go against his living will wishes?  Will this harm him if we have to "make him comfortable?"  If he knows what is going on around him does this make the living will void since he is alert?  If he cannot keep his eyes open - is that an indication of what his quality of life will be like?  What exactly happens (medically) when you "make someone comfortable" aqnd if he cannot speak how will I know if he is in pain?  His doctor is on vacation and the attending who is covering for him does not spend more than 2 minutes talking to me.  I am 31 years old and faced with life changing decisoins and I want to be informed.  Thank you for any help you can provide.