You do what you need to in order to stay sane. Only you know what you can handle right now. By the time he gets his car and license back, he will be even deeper in his depression and drinking so it won't matter.
You can't plan around the unknown, only what is which is he drinks until he passes out which upsets you. He isn't in treatment so its like pushing a big drunken boulder up a steep hill. It will roll back on you again and again until he decides to make the move towards treatment on his own.
Try to focus on you as best you can. Therapy or al-anon may give you the support you need to deal with the anxiety and sadness about seeing him basically destroy himself. It is very heartbreaking to watch someone with so many talents and gifts self destruct. I do understand. Hang in there. bb