Colin, I believe that there are more than a few members using those thermo-cubes. A good idea, no doubt, but I still prefer a H. D. timer set to go off about 2-4 hours before I leave, depending on the temps. outside. The only time I plug in for all night is when it drops to zero or below, other than that I use the timer. It uses less juice and is more than enough IMHO.
Scott W.