I know what you mean keg, but I can't think of the name of the mini series. The story is an asteroid is going to hit the Earth. A girl scientist gets caught on a train in a tunnel and she has this 'gas' that suspends time for all the people in her carriage and they wake up 15 months later (but its really 15 years later) and Sheffield has changed into the tropics. They all head north in a Mercedes Sprinter van (that starts first time!) and get to this place (which looks uncannily like a power station) to find her boyfriend who is now about 70; so she mercy kills him!! (nice girl!), but I just can't remember the name of it. It was about 5 episodes.