Ive never had a crèche, mostly mine farrow in a converted stable in the barn, then depending on weather, temperature they go outside at a week or so. We have farrowing rails and a creep area with a heat lamp in the stable, but once outside just an ark and a large pen. We have auto drinkers which they can't reach when tiny so I put a heavy dog bowl of water down for them. They don't stray too far from mum, and soon come back when she calls them. My friend farrows them all outside all year round, no rails, no crèche in a massive field, it's quite funny watching 2-3 week old piglets charging around then realising mums about an acre away! But they soon run back! Good luck.