Well it depends, then, how far away he'll be. Will he be further than he would be while he is at work? I suppose, though, when you've been drinking you do sleep more heavily, so he might not hear the phone.

If you had such a quick labour last time, maybe it's not a great idea for him to stray too far from home for an all-nighter. I'd say he should go out drinking, but he shouldn't stay out all night long. There's no harm in coming home by 12. It is a little bit of a limitation, but since you're sacrificing 9 months without alcohol ... Also, coming home by 12 means he can't drink all night long. I wouldn't want a wasted man by my side stinking of beer when I'm in labour, that's for sure.