I told my husband I could no longer live with him, he put our children in danger and I was done with the craziness. I said that the marriage was over as of now, and that the only chance I was willing to give it at all was if during the next 6 months (whilst we were living seperately) he gave up drinking and demonstrated that he could maintain that for at least 3 to 6 months, and at that point we could then talk to see if we were both willing to work on our marriage (counselling etc).
He took 10 weeks to move out, got himself signed off work with depression, and drank himself stupid, raging at me. he didn't give up drinking for a single day. The distance and clarity that not living with him gave me was enormous, the relief was wonderful. I gave him a big, last chance, he didn't take it, and that time allowed me to see that any pretence at giving up was just that, a complete fake.
We have children, age 7 and 2, I laid down ground rules from the beginning that he could not have them unsupervised, no overnights without a mutually agreed adult there.
He has fought this (with me) but I have held firm, even when I felt myself waver. I no longer waver. I currently supervise his visits with the kids myself, but am moving towards refusing to do that due to his behaviour.
The seperation didn't work out as far as saving the marriage, but it worked out in that it saved me. My ex has no intention of giving up drinking, he never did and that much became crystal clear during the seperation; that's his decision, his life and good luck to him.