It's tough to detach or get problem family out of your life. I'd start with small easier boundaries to maintain, enforce those. Also tell him with no fan fare, lectures etc that you will no longer carry him on your insurance. Maybe counter his response a little bit but don't let it turn into a debate or negotiation.
And in yes in a minimal way remind him he is an adult. Not a child whose playground is a bar. Adults pay their own way. Seems to have money for alcohol. Again don't let things spiral into a debate or argument.
Support vs enabling is a fine line to walk. Trying to manage or minimize the consequences really doesn't help either unless it's your butt on the line.
Stay safe, sounds like you are on the right path.