As kittykitty pointed out, they don't come home from rehab all better. At best, they come home with a tool box to use when cravings hit, and hopefully, a little bit of self-awareness of how and why they became an addict. Often, people think if our addict will just stop using, then things will be okay. Rarely is that the case. It's when they come back from rehab that the real work begins, and it is a long, long journey. They will have to learn to face life on life's terms, without running to the bottle for comfort. It's difficult. I can say this because I too, am an alcoholic.
My suggestion is that you continue to put the welfare of yourself and your children first. Your husband will recover or not, but it has nothing to do with you and whether or not you are living with him. If he is serious about it, you will see it with your own eyes in due time. Until then, stay in the here and now and don't waste time worrying about the "what ifs."