Thats a cool but disturbing story why would you not get someone to keep it for you when you are traveling.Or have a heated shed or indoor enclosure. But he is alive and well so I guess everyone gets lucky sometimes.
Looks like maybe a Hermann? They seems to be pretty popular in the UK
I can't believe they kept him around for a whole month, thinking he was dead! But I'm glad they did! He must have gone into some sort of emergency hibernation?