Once you are married to him, if he drinks and drives; and he will, hurts or kills some people, your assets can be at risk. Everything you have worked for, anything with your name on it.
You may also be liable for his debts, and believe me, alcoholics are notorious for uncontrollable spending.
The gaps between binges will shorten and eventually he will drink every day. Quite commonly he will lose a job/ many jobs. You will become his caretaker, maid, financier, and bail bond person.
You can still stay with him but THINK about heaps of REALISTIC RISK and since alcoholism only gets worse over time (unless he chooses sobriety) and he may never do that, you tie a legal bond that can and will enslave you to the above and more, not to mention emotional heartache and tragedy, aside from legal/financial.
Alcoholics love nothing more than to find nice people like you that will enable their drinking and cushion their falls.
They are expert and manipulating and making us feel guilty and sympathetic.
Don't jump into that pit.
Love him in a safe way, not in a legally binding way.