Welcome.
Your 2 year old may be perturbed by the change involved in living away from his father for a part of the week, but he will grow up far more perturbed by thinking that addiction is common and acceptable in is day to day life.
Ultimately, this is what made me leave my XAH. I couldn't bear the thought of my daughter growing up and thinking that a "normal" family involved the madness of drug addiction and alcoholism. I imagined her as a grown woman, involved with a man like her father, unable to get herself free, and then I realized that I had to leave, to give her the opportunity to experience a different kind of childhood.
As for the "Monday promise", it's just WORDS. And you probably know by now that when it comes to alcoholics, words don't mean jack. Actions are what you need to be looking at. What is he DOING to change the situation? Is he being consistent in his actions?
A big decision on Monday is a mere sneeze in the direction of the lifelong journey that is recovery. Nothing more.
Time to find some Al-Anon meetings and attend, if you can. Also time to figure out what other options you have should the "Monday promise" fall through.
I'm glad you found SR. Please feel free to post and read as much as you like.SR is always open.