u did not mentioned about heart function of ur father. it is true that prognosis is varies with patient to patient no body can exactly comment about anyone's life span . for better and longer living i advise salt and fluid restriction and monitoring of bp and serum electrolytes that he will not have fluid over load as well as arrhythmia
. he also has to continue his diuretics to mainntain out put but as u mentioned his kidney
function is not good so he may require dialysis
bur after naphrologist consultation, this is helpful in acute condition to remove access body liquid, also in acute condition he has to be given iv diuretics for the same..