My Dad had to deal with this all the time. His brothers and sisters were heavy drinkers. The oldest died of scorrocis of the liver, malnutrition and yellow jaundice at 36 years old. I never touched acohol because of that, and of course I was saved at a very young age.
The youngest Dad got out of hospitals and bars all the time. The other brother in the army came out an acholohic so I have seen it dealt with. The other went in and out of Acohol treatment finally dieing of scorosis.
So I have seen Dad gently speak to his brothers while fuming underneath. The oldest, Dad said made what amounted to a death bed profession of faith. The next to the youngest DAd had many conversation with about the Lord and I was also able to preach to him and talk a little with him after dad passed. Not really sure he ever received Christ and the catholic religion he was in didn't help. I was asked by his son and stepchildren to preach two times one they called a wake the other at the graveside. I was able to preach to a catholic priest at the graveside and one of his step sons who was is a Jehovah witness.
The youngest lived close to me when I was pastoring and he and his wife and sometimes his and his wife, came to services. The one I preached the funeral too also attended church a few times. I have learned over the years you must treat someone with acholic addiction or even drug addiction very gently and not rail at them. Letting them know you don't approve while loving them as a soul needing salvation. The problem is deep centered not just sin although sin is the root. The cravings are tough and the desire great with those addicted. They need prayer and help from a good christian psychologist or if you have a Christian Counsellors license you can council them but it is difficult and they will never be fully cured, they will need to be helped through life with tis.