I'm guessing the real key to an intervention is that those having the intervention have to be able to carry out whatever boundary they set up in the process of staging the intervention. You can set boundaries without an intervention. They will help you deal with your A, whether drinking or not.
No judgement here...those that come to SR are often in crisis, waking up to their crisis or have been through it already and are paying forward what they have learned. Our paths have strong similarities, but subtle differences as well. Only you know what is best for you and your relationship with your A.
Success stories here come in all shapes & sizes...there is a sticky to some good threads on success stories. I'm not sure if anyone has had a "successful" intervention or not.
Welcome to SR, bmf1978.