|London to Key West is a 13 hour journey|
Then because of the martini(s) consumed, the jet lag is hours from kicking in, so a detour via Bourbon Street pub is inevitable. Hit the pillow after midnight. All in one day.
As I write (August 2014), I've done the London to Key West trip 18 times - 18 flights out, and 18 flights back. Yes it's a long way but it's worth it.