I agree, though IMO UK fits clearly in the North in case there was any doubt!
I suspect it's a wine drinking vs. beer/spirits drinking thing, but I'd like to think the southerners appreciate that a hangover is particularly nasty on a stinking hot day
It's certainly apparent that in English culture, it's fun to laugh at someone who's too drunk to walk. In Italian culture the same situation would invite disdain.
regards
Ian