Something I'm going to do one day
Mate of mine flies bizjets and was coming back to Long Beach from Phoenix. They were running late and my mate was flying back to the UK that night for a holiday. It was rush hour and the traffic at rush hour is a night mare (as you probably know), and they didn't have very long to get to LAX...So once they landed, the Citation owner wheeled out his jet ranger from the hangar, and flew my mate to LAX....!
Wonder if you could get a SVFR from S to N across the Heathrow CTZ "via the overhead"