I was right there where you are last year.
I threatened to leave last January but talked myself into staying for another year. (Truthfully, I was scared to leave and was looking for any reason at all to stay).
And like you I considered what it would be like to not have an alcoholic in my life. And I planned for the day when the other shoe would drop. I think I read here that spouses of alcoholics get to a point where they are always waiting for the final straw. When my breaking point finally arrived this January I was calm, focused and ready.
And it feels so good looking back after 6 months of peace and sanity.