Hope the neighbours weren't watching!
It's a lot harder doing kata in boots in several inches of snow and outdoor clothes make it difficult to be snappy with your moves. However, it was very invigorating and enjoyable out in the fresh air. I went through the kata about 6 times which got me pretty warmed up despite the 0 degrees temperature today!
I think I should do this more often, it adds a new dimension to training.
And just to show that my sensei kept his half of the bargain (though I expect he was planning to train outside all along anyway, he's pretty hardcore) here's the photo he sent me:
Okay, now I'm challenging you to train outside in the snow and post the evidence!