Dedicating a song to my dad

Yesterday I had to make the difficult decision of telling my dad he isnt walking me down the aisle or doing the father daughter dance with me unless he gets clean and sober. My dad is an alcoholic and has been for a few years. he hasnt always been one. Growing up he was a stay at home dad and the two of us got very close.


However since I was in high school to now he has went down hill. He has had a few close calls in life, such as surviving going into cardiac arrest a little over a year ago. But never learned his lesson.
I really had no clue what else my family could do to get through to him. I have always dreamed of him walking me down the aisle and I picked out the song Cinderella for us to dance to 6 years ago when my FOH first got together. However, the man who looks like my father now is not my dad but a shell of the man I knew who is completely empty. I thought telling him this yesterday might get through to him. I have 8 months for him to get help. I want to be hopeful he will change but I highly doubt he will.
As of right now my dad is invited to the wedding just does not have a part in it. My dad is not a violent drunk. He doesnt know what is going on, becomes highly emotional, will say something inappropriate, and is mean to my mom. My wedding is dry with possibly a small cash bar or having wine at the tables only during dinner. Please do not give me your opinions on a dry wedding. If he doesnt get better would it be bad if I dedicated a song to him, like many brides do for their mom. The song would be dancing queen, as this was a song the two of us would sing and dance together to since I was dance when I was little. I want him to know I still love and care for him, but I cant let him be the one to give me away in the state that he is in.
Do you think it would be stupid if I did this as a back up if i don't end up doing the father daughter dance with him? Or do you think it would just be offensive and remind him more of what he couldnt do.