Hi VT sister! Nice to "see" you again!
Glad you were able to give him the news. And glad you gave it a more realistic date, October 1 is certainly very generous and plenty of time.
I used to feel bad any time I cut my brothers off from the various forms of enabling I had been providing or anytime I asked them to do anything that for me, a normie, is just a normal aggravating part of life.
AlAnon helped me turn my head around and stop thinking that I have any control over outcomes anyway! It helped me to stop thinking about them solely defined by alcoholism.
Him moving out could be a good thing, a bad thing or an entirely neutral thing - but it's his thing, and it's something we all "normies" go through all the time and handle and it gives us confidence and pride in our strength and abilities - so let it go, let it be his situation to solve, he's an adult.
Now you can start planning the changes you'll make to the space! How exciting!
Peace-
B