I have size 8, broad feet and my calves have a whopping circumference of 44cm around their bulgiest bit. Try as I might, I can not get Mols or Meses to fit. But I have discovered some good alternatives that fit at CLarks. These are a similar style but more generous sizing. And about £45 cheaper!
I also ordered these, but the zip is only half length and the boot does not open up wide enough for me to get my big feet in! Shame as the they looked like my calfs and feet would have fitted if I could have actually got the boots on.