ToughestRaceonEarth:Iditarod: On this annual sled race in Alaska, mushers and teams of dogs cover almost 2000km from Willow to Nome. If the prospect of below-zero blizzards and ice up your nostrils doesn’t deter, this year’s race slushes off on March 7. Wednesday, 9.30pm, Discovery. TheRealSeachange: Follow risk-taking Australian families and couples as they follow their (often impossible) dreams of a simpler, more satisfying life. Friday, 8pm, LifeStyle.