I had an eyebleedingly fugly hi-viz raincoat I got for a fiver out of Bethany(longsleeve-T underneath was more to combat its hilarious unbreathability than the cold), pair of waterproof breeks, lightweight workie's gloves and a laptop bag for nine quid total out of the Omni carboot and hiking boots for two quid at the Chesser carboot. Oh, and a beard I got for less than free.
It certainly passed today's test with flying colours; we'll see how it does when it gets proper cold.