Mine sure do shiver and timber when we go north too. (as I do too).
try this link. if you do a search on any search engine it will lead you to many many many patterns for knitting. just put in "free dog knit patterns". I crochet but don't knit. well...I do a pretty mean flat piece of nothing pretty good.
here is this link and listed at the bottom is a tuxedo. I had my sister knit that for mine and it is really cute. be sure to post a pic of any that you make. I would love to see it.
http://www.knittingpatterncentral.com/directory/pets.ph