Since this is a very real possibility for me right now, I have an answer that I'm already planning to put into action.
My final days would be spent with family and friends, enjoying the sensual things in life like time in nature, tasty food, sharing laughs and good memories (along with tears too of course). I'd also have some healthy alone time. My life will not radically change because it's about to end, I will just be amplifying the good things as much as possible while allowing any emotions to arise so I can make peace with what's about to happen.
Having experienced the energy of near death many times in my life, I believe in my core of cores that it is a natural process, just like birth. There are mechanisms in place, in our animal biology and also in our spirit, that make it a guided, forgiving process. So I know that I don't have to spend my final days numbing out because when the time comes there will be something... as vague as that sounds... that will help me through.