Thanks for the info everybody. It's been 10 years + since I've visited any of the islands. Me and the then wife (she was the only driver) used to visit Scotland around the festive season, so time was limited (as were some ferries), a car was needed for us, and camping in the Winter was totally out of the question!

I had no idea about RET - what a great initiative to keep the prices down and increase demand and help communities. I've been thinking recentely about going to some of the islands which I haven't yet managed to get to. I've never been to Lewis, so that's top of the list - In the Summertime this time though. And as a non-driver, I might have to get the bus and walk a bit too!