I agree. Heat tape is good for keeping small volume containers free from freezing, such as pipes or hoses, but not sure about larger containers such as buckets and such when the temps really get cold. I don't know of a way it could be utilized to keep chicks warm enough either.
I've often thought about making a fleece, down-filled "chick mama" with chicken wire inserts so that it can be bent to a needed shape, wherein one could brood chicks without a brood light or broody mama. One could heat a few bricks, wrap them in flannel, put them down on the floor of the brooder and place the fake chicky mama on top, with space enough under her for chicks to huddle under and fleece fringe hanging down like feathers around the edges to trap the heat while still allowing chick access.
Or the chick mama could have a place for a heating pad to be inserted to create a warm "chicken" over the chicks to give a more natural feel to the whole brooding experience. It sure would eliminate stress over using heat lamps and such, while providing chicks with enveloping warmth sort of like the Ecoglow but without the price.
I might see about fleecing some of these cheap meat roosters or my older hens of their softest under feathers during this next processing and using the feathers to make a chicky mama...maybe try it out next spring if I'm still here.