FWIW, these are designed for use with roof and gutter heater tape. I considered using these for that application at my old home to help with an ice damn. In the end I opted to simply maly nually plug them in since the issue only occurred once or twice a year and not even every year.
I actually thought about using these again at my current house to control a light bulb under a shop sink to keep pipes from freezing. It would be a good idea to use it, but I decided to just leave the bulb on at all times to avoid cycling which is what typically causes failure. I'd rather burn a few watts when not needed rather than bursting pipes again...