@ScottishMouse
I've tracked down a size 10 at the welsh outlet store and they're sending it to me - was busy today so only tried on the 8 while it was getting dark and despite the fact that I'll have to pay to return the outlet coat, I think it's worth a try
I have a couple of suggestions for you (am sure you've already tried but you never know!)
this Kin coat (only one left in an 8!) looks quite interesting with the ripply quilting)
kin coat
a couple from Sweaty Betty - I particularly liked the reversible one, but they both look so warm and cozy:
reversible coat
cocoon puffer
.. and I don't know how you feel about Barbours? I find them really warm and practical - here's a Margaret Howell collab:
MH
and there are some quite nice coats in this collaboration with the House of Hackney:
house of hackney