Liz Goodchild, 45, her wife, and their seven-year-old son split their lives between a one-bedroom loft apartment in Macclesfield and an 18th-century, five-bedroom farmhouse in rural Germany – and find the cost of their bills vary dramatically. “What’s mad about our life is that we live in a one-bedroom apartment in the UK, all on top of each other, and then in a massive house in Germany,” says Liz. “It’s like switching one life ‘off’ and another…