Honey. You need more information than you have given here. Acute kidney failure is very rapid and would, I think, need a more accurate test than some blood tests over Christmas.
If the staff member has said life span is 6-12 months that is wrong on two counts. It is not for her/him to be telling you that and as my husband lived for eleven years after diagnosis...6-12 months is incorrect.
If his kidneys are failing now you need someone to be taking some action, even if it is to make him comfortable.
If he is passing no urine don't force water down him.