Oh dear, it’s so sad. As everyone else has said, there is nothing at all you can do in terms of “fixing” him. That would only happen if he decided for himself that he wants to change and, sadly, that might be never.
It sounds as though your focus needs to be on his wife. Alanon could be a brilliant start. Could you offer to go with her (if you are willing)? A lot of meetings are probably still on zoom- maybe you could sit with her through the first few? It will probably be very emotional for her. If she has the money, finding a counsellor who specialises in addiction could also help her as somewhere to vent and with getting control of her enabling behaviour.
She is desperately trying to control the uncontrollable here and getting dragged into a really dysfunctional situation. It is not her fault but it is not a healthy reaction and she really needs help to strengthen her responses.
Alanon/counsellors would help her to see that she has no control over whether he drinks and drives. Good on her for thinking about the risk of this to everyone else but this is totally the wrong way to react.
A more healthy reaction is to refuse to ever buy him booze. If he then goes out drunk in the car, she reports him immediately. every time!
I know this is hard and she might (misguidedly) feel really disloyal, but it is MUCH more likely to help him in the long run. He will start to feel the real effects of his drinking and maybe that will eventually cause him to seek help.
Really good luck to you all. It is such a horrible disease.