Sleeping arrangements

I’ve written a few times here about my husband’s drinking and his snoring and sleep walking disrupting my sleep. I have accepted that his drinking has nothing to do with me and that I want to stay with him. I do however think I still have the underlying hope that he will change in the future…
I tried to set a boundary around the disrupted sleep, in particular because I’m 5 months pregnant and am sleeping tonnes! I find it hard to function to my maximum the next day at work if my sleep is disrupted too. I tried sleeping on the couch but found it wasn’t great for my back and hips. He also told me he was sad that I wasn’t sleeping next to him.
Last night on a night when he usually doesn’t drink, he came to bed quite a bit after me and I could smell alcohol on him. He proceeded to snore his head off and I retired to the couch to get some sleep. Again the sore hips and back…
So this morning I asked him if he is drinking to sleep in our spare room so I can sleep in (relative) peace.
He agreed, but I’m not sure if I can set a boundary for someone else to do something? The main reason I was leaving our room was so I had control over the boundary. But given the circumstances, I think I’m entitled to the comfy bed! (and he is not arguing) What do you think?
PS: There is maybe 10% of me that hopes the boundary also makes him change. Argh!