Op, I think you have been given a particularly hard time on this thread over a situation that I and others (although seemingly not on this thread) would not be comfortable with.
The fact of the matter is that if you are caring for children, then you should be in a sound state of mind, or at the very least, 1 of you should be. Yes, emergency situations are fortunately rare, but is it really worth the risk? I know for sure that if my dd needed me, for whatever reason, I would not feel comfortable picking her up and attending to her, if my mind was fuzzy from alcohol. No not everyone has a car, so the being able to drive a car is a slightly redundant point, however you may end up in a situation where someone needs to react quickly, and if you are all drunk then noone can.
I find it quite astounding that the rare event of an emergency is enough for people to think getting drunk is ok, but in other scenarios where no responsible adult is available most would be appalled. Example, children are in bed, you need some milk or whatever, so you quickly pop to a neighbour or shop. Is that ok? No of course it isn't. Why? Because in the rare event an emergency or anything happens in the 5 minutes you are gone, something could happen, and most people realize this and would never ever take the risk. How is an emergency like this any less likely to happen when you are drunk?
Drinking culture in the UK is an absolute mystery to me. Perhaps it's because I have family in the med who would never even dream of "planning" to get drunk. It's just not the done thing. For some reason the UK seems to view this not just as acceptable behaviour, but actually normal behaviour, and those of us that don't engage are the strange ones!
Op, stick to what you believe, you are being completely reasonable in wanting at least 1 sober adult in the house with the children. Don't let this thread make you think otherwise.