I am a bit obsessed with coats and have just bought a North Face Arctic Parka for freezing football sidelines, there are quite a few on Vinted for around £100. I have a seasalt Janelle and don't really get the hype, I like the length, but the peak on the hood looks a bit ridiculous and it's not that warm.
I do have a dryrobe type coat from Tesco, it was half price, I think because it's leopard print(!) and it's the snuggliest, warmest thing, but I feel a bit, erm, conspicuous wearing it!
Have also had a Rab deep cover parka in the past that I would recommend!