The snow has mostly melted away - it was a warmer afternoon and the Sun finally came out. It was shining through low cloud towards sunset so I was able to get a photograph of the disc that wasn't overexposed. So I was able to prove that the disc of the Sun subtends an angle of about half a degree at the eye (ie half the width of a little finger at arm's length). This is the same as the Moon, which must work because the Moon almost exactly covers the disc of the Sun during an eclipse.