Assuming they are similar levels of drunk, one party didn't get them into that situation specifically do that without the other one's knowledge, and they're both sloppily initiating drunken horny on each other, then sure. But really it would be worthwhile assessing the situation afterwards to see what actual harm/trauma has happened. I say this as someone who has drunkenly initiated things and its either violated a boundary or I've regretted it later.
I think the idea of having consent as this hard line, unforgiveable sin thing is probably not a good way of viewing consent. It's kinda puritanical. (e.g. most jobs are non-consensual in a puritanical sense, I would not be doing most jobs I've had unless I needed cash for rent/food, but we also learn to forgive people who help us get jobs we wind up hating. Also consent isn't just for sex)
The latest episode of the podcast Multiamory, which is focused on polyamory stuff but this episode was more general, actually has a broad discussion on this if you want to check it out. I disagree with a couple of points here and there, but whatever.
Not sure about the specifics of the law (I never drink alcohol, so I never bothered to read up on it), but from an ethical point of view, it highly depends on how drunk the two are. Is one of them significantly more intoxicated than the other?
Generally speaking, I'd recommend against it unless you aren't THAT drunk. When you are significantly intoxicated, you are less likely to be able to express your discomfort or notice/recognise your partner's discomfort, so there is always the risk that you, while drunk, might think you're having consensual sex while the reality was that the other was unable to consent and actively wanted to stop, and you misunderstood their intent.
Obviously it matters greatly if the two already know and trust each other, and are more likely to recognise when the other is uncomfortable compared to strangers hooking up for a one night stand, so there is another layer of consideration.
Generally speaking, probably best to avoid getting hammered and having sex.