Sourdough starters are tough and flexible - a small handful of starter dough, whether in a miner's trousers in the frozen Yukon goldrush, or in the plastic tub in the modern kitchen, and you have all you need.
You can freeze it - but we left one in the fridge for 2 weeks, which was quick to grow back when fed. The other three, which I needed to use the day I got back, we took with us, for a holiday in Cornwall. A handful of flour and water every three of four days was enough to keep the bubbles rising.
