I absolutely love these boots...
I've been trying for yonks in all the high street shops to find a good pair of cosy, flat-heeled winter boots that actually fitted properly round my (normal-sized) calves - and these are perfect! So many other pairs I've tried over the months have been hugely 'baggy' around the calves, so you end up looking like you're wearing a bucket on each leg! Drives me crazy!!
Anyway, these boots are gorgeous - they are an absolutely perfect fit, and even if you do have slightly larger calves, the buttons you can see in the image on the top bit of the boot-leg do actually undo (they're popper style ones), so if you did need a bit of extra room, you could just undo the buttons - the material still stays upright and won't flop over, btw - unless you deliberately want to fold it down at the top, which you can.
I'm a UK size 7 and the pair they sent fitted perfectly - with socks on underneath or tights - so the sizing seems to be spot-on. The material is lovely and thick and the fur lining is so cosy and soft. They also look quite slim-fitting when on - some flat boots can look a bit chunky and make your feet look bigger than they are, but these are very flattering.
Really love these - I would have paid full price for them, they're that good, but got them on the Amazon sale so couldn't be happier! Treat yourself!