Congratulations on your beautiful quilt. Could you make another one to give. You didn't expect this to win and it would be nice if you could keep it. I'm a very giving person but doubt I could give a winner up but would happily put in the time and expense to duplicate it as closely as possible and give to the promised person. I'm sure they'd understand.
I'm finishing up a quilt that I believe stands a good chance to place and because of that, won't enter it into the quilt show because I know beyond a doubt my daughter in law would treasure the quilt which is for her youngest daughter and would NEVER allow my granddaughter to use or enjoy that "special" quilt if it would place. Since this quilt was made specifically for her, I'm not taking the chance as it's important to me that my children and grandchildren treasure my quilts by enjoying them to the fullest and I mean using them. They tell me they feel my love in them every time they use one and those are my blue ribbon quilts.
Give it some thought. You could always put it in your will that it will go to that person or survivors once your gone but I definitely would make another one and keep this one. Just my opinion. Good luck with whatever you decide to do.