I agree with what Andrew said about tweaking your plan along the way.
I've never really had a plan in the past, and today is my second day sober.
My sober plan is to plan ahead two days in advance - I think that will work for me.
I'm lucky and grateful that my close family and friends don't drink, and they know my issues, so as long as i'm with one of them, I know i'm safe. It's when i'm alone, that's when I really need to be prepared.