Hi daughter
Great boundary, very clear, precise for both of you and you have given him something to think about - that you dislike talking to him when he has been drinking.
After reading the thread it sounds to me that you have become anxious about stopping at a liquor store on the way home from the airport and feeling uncomfortable about it. My suggestion is not to make a big deal about it, you are driving and if your dad suggests stopping, just say there is no need to stop and that you have some wine at home that you can both share. (you mentioned you are social drinkers) If he persists, just repeat that you have some wine at home but it can be reaccessed tomorrow but for now you just want to get home as its been a long day (or something along those lines).
Have 'one' bottle of wine at home.
You cannot control your dads drinking just by not supplying it or allowing him not to buy his own. He is an adult alcoholic and will find a way to drink even if you dont want him to. Trying to control his drinking is only going to upset you more as you are setting yourself up for failure.
You have already explained that you can not have the boundary 'I will not allow alcohol in the home' as you do.
To me, this is not really about his drinking but his behavior when he has been drinking that you don't like and this is something that you can control of how it will effect you. Set up some boundaries for yourself whereby if your dads behavior is starting to annoy you, simply say I am tired and I am going to bed or you are going for a bath, visit a friend or anything really to take you away from it/him. This is detachment and many of us living with alcoholic partners practice this frequently otherwise they would drive us mad.
Hopefully I have contributed to another alternative boundary to think about and you end up having an enjoyable visit with your dad.