They did this for me once on an Intercity or whatever they call them these days. I fell asleep and woke up to my Mum waving at me from the station platform in Lancaster or somewhere wondering why I had not gotten off the train as it pulled out of the station. The conductor was kind enough to stop the train at some random cattle grid barely-even-a-platform in the middle of nowhere and radioed the train coming the other direction to pick me up. Bless.