In theory, baby wipes were a good idea. I managed to keep my bike nice and sparkly through the early part of winter by taking a couple of wipes and removing dirt and gunk from the frame after each commute.
In practice, the plan failed; once it actually got cold, the wipes just froze to the frame. If I had a microwave it might be worth heating them up (in the style of airplane hot towels!) and giving that a go.