Prevent Frozen Waterfalls on Those Cold Winter Nights with a Wrap-On Pipe Heating Cable

Houstonians, where I grew up folks pretty much rejoiced if a January overnight low only dropped to 20° Fahrenheit, so your "nasty cold snaps" seem laughably warm to me. I kid you not, in seven years I've never worn my second-warmest coat here, much less my warmest - and the best gloves are still somewhere in storage, too. However, I realize that not only are the human beings around here unable to endure sub-freezing temperature, local houses haven't been designed for such temperatures either. So we are prepared: for example, we bought some of those 99¢ foam covers for our outdoor faucets and picked up some foam pipe wraps.
The Problem: Exposed Pipes
One inexplicable local plumbing practice - don't me why, given Houston has a hard freeze every few years - is to pipe to near the edge of the slab with PVC, then finish bringing water to the house through an exposed copper supply pipe. Yep, naked metal pipe outside the house; a veritable full-employment plan for local plumbers if there ever was one. I've outsmarted them, though, because I own a Wrap-On Pipe Heating Cable I'd bought several years ago for our Great (formerly) White Elephant on the Edge of the Prairie. No problems: even after several nights of low-twenties temperatures, we'll be fine -- though our plants probably won't.