Keeping him comfortable and out of pain, with the liver problems as well, probably means morphine or other opiates. They're the safest for the liver. They could well be sedating him, or have been sedating him a lot to begin with. As you get used to them, they still knock the pain but don't necessarily sedate you so much.
The i.v. - necessary for ongoing nutrition and probably also how they're giving him the analgesia; giving him anything orally is not a good idea with the varices.
It could mean they won't interfere to drain the ascites, but if it makes him uncomfortable, they might justify it (a drain). I think you might need to be guided by the medical decisions of his team on the spot; if he shows signs of improvement, it could move his status from end stage to long-term/recovering. But I really don't know, I'm not the one there. It doesn't sound good, especially if he's not given any indication of staying off the grog if he does make a good enough recovery to drink anything at all. It does sound like it will be a long time before he's even permitted to sip a glass of water, let alone a beer (or stronger). Not only would his body have to recover, he would also have to have a change of mindset in order to be able to give up the drink.
It sounds like his liver is the main organ in deep trouble. The liver is also the internal organ most capable of regenerating; to a point. But it needs help, and past a certain point, it just can't do it. If your husband makes enough of an improvement, then he COULD possibly improve enough to be shifted from ICU, but it would be a very long time, if ever, before he could return to anything like a normal life. Not with the damage you describe.
If what your sister in law saw is the beginning of at least a partial recovery, than hopefully soon husband will be able to reinforce what you've been telling the doctors on his behalf ie no heroic measures. That would mean no getting the paddles out when his heart stops; no intubation if his sats drop slowly; just maintain status quo. In some cases it also means stop nutrition, but if he's already receiving it, I doubt they would withdraw it.
I'm so sorry you're all going through this, Linda.
Marg