Fairymum, if it's that much of an emergency I'd need an ambulence. Else I could call a taxi, or just walk, take the bus...WE don't have a car, so wouldn't matter if I was illegal to drive. I don't like getting plastered, anyway... I do know people that say that they can never drink in case they have to drive at short notice to hospital, but if you like a drop at all, how can you manage to refrain all the way until they're 18? When they might be too pissed to drive themselves, either?!
I've never had to go off in the middle of the night, truly never had an emergency, so can't imagine it as a high risk.