> One scenario would be somebody in an airport and security officials are searching your device
No Heathrow connection necessary. “The law has extraterritorial powers, meaning UK law enforcement would have been able to access the encrypted iCloud data of Apple customers anywhere in the world, including in the US” [1].
[1] https://www.ft.com/content/bc20274f-f352-457c-8f86-32c6d4df8...