this is an old argument.most wear is one when cold.also the fuel washing the bores ect.sitting with cold engine running must be worse than driving easy.
mine is very slow to warm in winter[well above 0cel],I often have the radiator air flow partialy blocked off.so I can understand the problems in cold areas.10-15 km before overdrive is allowed to shift.
I looked at block warmers and pumps,if any one knows of a good one well under AU$400 I like to know about it.
Thought about a jug element and a pump [off merc,bmw,vw or vectra].
add saftey switches so one dont fry.