@Namechangeisgood I'm going to try to get to the local Seasalt shop tomorrow and try it on. I've had a Janelle in the past and found it quite warm, but perhaps the style has changed? The Pentawan looks closer to what I was hoping to find (no fleece, but has some padding).
Jack Murphy and Baleno look brilliant and exactly what I was looking for, although not 100% my style (which is more minimalist / simple black coat) However I'm desperate for something comfortable at this point. Will have a look online, thank you!!
@CaramelWaferAndTea Yes, I wanted to buy the Arket one, but was too slow and now it's sold out 
Many thanks for all the suggestions everyone, will keep looking and trying them on. I have wondered about waxed cotton coats (some are quite long), but I'm put off by the lack of hood and worry about how waterproof they might be? Do people wear a hat with their waxed coats (not sure I've seen anyone wearing one around here...).