So I woke up s'morning, got breakfast and was sitting down with it. I reached for my iPad, switched Radio 4 on and it sed "No inteweb connection". I looked over my shoulder and the router had indeed a red light on the front. I thought "Bother" but thought I would just finish Muesli and Coffee before buggering off to press restart.
But about 1.5 minutes it fixed itself as if by magic