It's lovely, and really catches the feel of a frosty morning.
Technically, it looks as if it could do with a little more sharpness, particularly on the wall. I'm not sure, but the EXIF data suggests that you shot hand-held - if you'd used a tripod, you would probably have put the ISO down from 640, and allowed a really long shutter speed. I admit it - I would do the same, and body-based IS in my camera is not a good enough excuse for it. Tripods really are best for this stuff!
Looking at the histogram, the highlights are slightly blown - if you have a RAW file as well as a JPG, you can probably sort this out (it seems to work - my digital editing isn't up to much, so others will know a lot more than I can offer on this). I start from the frost looking slightly blown, and the histogram confirmed it.
You did ask for detailed and honest criticism - apologies if this is too much so.
Artistically, I don't think you could do much to improve this shot - though there are probably several different compositions that would work (and you may have tried them all, of course!) But they would be different, rather than better.