After being abandoned by his friends and family, an alcoholic father looking to turn his life around must battle his addiction and confront his own behavior to win back the love of those who matter most to him.

How about this? "After his family abandons him, an alcoholic travels to Napa to visit old friends who help him confront the issues that led to his addiction and discovers an unexpected threat to his recovery and his family."

Worse than not being invited to the wedding, having his daughter's stepfather giving her away.
Create conflict by having one daughter rejecting him and the other trying to motivate him to kick the habit out.

Thanks dpg and Richiev - really helpful.