I'm sorry, this is all really difficult to deal with. But I am a big believer in Marie Kondo too and am excited about that part for you!
Just an observation... my neighbor (wife left him a couple of years ago, has a S4 and D9 now) doesn't have any sort of alcohol problem, but routinely naps now when he has his kids. it is WEIRD. I mean, I know he totally naps on the days he doesn't have his children but think it is so strange that he still does it when he has the kids. I've come to believe that it is part of his routine and he can't kick it, even when he has the kids. I know your H has alcohol problems, but it may not be that he's so drunk he's passing out when he has the children. he may just be lazy and self-centered and unable to not take his regular afternoon nap, even for his kids.
Regardless, I third the idea of your S12 having a phone for those situations.
M
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing