All good advice for a very bad situation ... reminds me of XA #1 and father of my two children.
I was a couple weeks to my due date and he wanted to go help a friend bring a boat down the coast and this was going to be an all day affair. I told him I didn't feel comfortable with him being hours away but he went anyway and sure enough I went into labor and had to get a friend to take me to the hospital.
He had to get someone to pick him up and they had to drive way too fast to get their on time for the delivery... about 45 minutes! Of course, I had to go through the worst of labor alone.
Being at that birth meant the world to him... we divorced years later but he would have been crushed to have missed it despite his irresponsible decision to leave town so close to possible labor.
So... I lean towards not getting too draconian on the birth part of it. However, there is no reason not to establish a no alcohol boundary if that is what will make you most calm and relaxed.
If you prefer to be a bit wishy washy at this time you have EARNED that right! There is nothing wrong with changing boundaries due to extenuating circumstances! It is ALL ABOUT YOU and that baby... whatever works for you right now.
You nor the baby need stress... it is not good for either of you. So... if you prefer him to move out ask him to do that for you. If you prefer him to sleep on the couch send him that direction. If you want him next to you rubbing your back and feeding you bon bons and peeling grapes then so be it.
And don't worry about whether you are doing the codie thing right or wrong or changing ultimatums and boundaries! There will be plenty of time to figure it all out one day at a time once the baby has made a safe landing and you are back on your feet.
Do try to get a good friend to come and hang out with you... that is a great idea.