There are many many posts here about people leaving and explaining the whys and hows of their plan. There are also many posts here explaining the whys and hows of people who have found ways to live in joy with with alcoholic spouse. Only you can decide which way is right for you.
You can't bar a man from his child's wedding. Nor should you or anyone else accept responsibility for his behavior, only he is responsible. If he shows his backside at the wedding, it's his problem. If it happens, as his wife you will set the tone. If you ignore him, others may follow your lead. If they ask, you answer simply, "He's drunk." and continue to enjoy the wedding.
I am so sorry for the loss of your father. Each of us mourn in our own way, in our own time. Again I remind you, just ignore him and continue with your life.
Stick around, I've learned much from the wisdom of others here. Try some Al Alon meetings, again, you can gain much and have nothing to lose but an hour or two of your time.