Glad I always park in the garage - shouldnt have to bother de-icing the car etc throughout the winter
Anyways, I rarely use my heated seats TBH.
I always have the car set at 21c - even when Im leaving for work early in the morning.
The car warms up gently and nicely, and the temp is maintained.
Sometimes I may turn it off when Im comfortable - but most of the time I forget and just leave it running to maintain a constant temperature. It also keeps the windows clear of mist.