I can tell you I've been where you are now. I continued with the divorce based on one idea. That if at anytime int he future M embraced long term sobriety I could always decide at that point if I wanted to attempt to heal the relationship. As it turned out two years after we divorced she did embrace sobriety and we did date. Unfortunately for M it wasn't long term sobriety and ending the relationship at that point was far less complicated.
Good luck.