I got a pair of similar last year, called Khombus (I got them while living in the US). That style tends to come up BIG. Guess they are intended to be worn with massive socks, but I found it a bit irksome as I hate having hot feet so don't often wear massive socks.
Might have to buy a pair of the sorel ones (I had been lusting after the cate the great ones, but they don't seem to make them anymore. Booo.