That looks like a good idea but with two big "but"s.
Firstly - my god, the price!
Secondly, it is usually the tap mechanism that freezes worst, so even with that, you'd have to defrost the lever.
It would stop having to pour hot water down the pipe tho to unfreeze the part overground. Might be worth it on a yard to keep the main intake unfrozen - I think the drain off is the big thing, but you'd still need to insulate the workings at the top.
