Finishing a post I didn't finish yesterday, but what Knight said.
Thats why i dont do it at a beach where people walk their dogs, i do it in the mountain wilderness, the type of place people get lost in and i would hike a few miles into it. Id Get rid of the rescue risk and its suddenly a very reliable way to go.
Yeah, I was primarily addressing OP. It's a horrible way to go, and you're still fighting yourself and your own raw survival instinct (as well as your body's obvious attempts not to lose its heat), but your chances of dying are a lot higher if you go somewhere
genuinely isolated (not somewhere people hike or rangers hang about). It can take time to fully die.
I skimmed over your post a bit. To be clear, before you fall asleep, you'll be shivering, etc. But alcohol will accelerate the heat loss somewhat. I've never drunk alcohol so I generally don't comment on things involving alcohol unless it's pharmaceutical, but that one is well known and easily verified through the literature.
I'm hesitant to link external resources or rehost them here any more. Google things like 'hypothermia chart' and 'hypothermia water temperature chart'. The data seems to be the same across sites. The other good chart to look at is NWS (National Weather Service) Windchill Chart, which shows time exposed at various temperatures to risk frostbite.
The problem is not getting out of the water and the drown risk vs. the time it will take to die of air exposure. Wet clothes do help with the conduction issue.
I just found this and it's pretty good. I will link it, and leave it at that. Anyway, you should always know how whatever you're trying to do is treated, especially if you can treat yourself if you can't go through with it to prevent further damage. But it has other good information as well.
https://www.princeton.edu/~oa/safety/hypocold.shtml
I'd rather drown for what it's worth, but it takes a lot of guts (guts in the sense of raw impulse or ability to override SI or whatever can allow one to subject oneself to pain, not courage).