The tyre hotel thing was new to me, if I get in a position where I need to have winter tyres I'll consider that. The fact remains though that, even though I use my car as my daily, due to my driving patterns I'd probably only benefit for around half a dozen times a year so I don't think that its worth it. I can appreciate that those of you living further north, or driving before the sun gets up etc, will see the benefit.
On the tyre temperature thing. I think that the majority of us know enough about driving and cars to know that getting heat into the tyres is based on a number of factors, including: road temperature, grip on the road surface, tyre make up, driving style. If you've got a TPMS with tyre pressure readout though you've got a built in approximation of the tyre temperature. The normal pressure on my tyres is 2.2 bar. When its cold the pressure drops to the 1.9/2.0 mark on startup. As you get heat into the tyres the air temperature in the tyres increases as does the pressure. So I know that until I get to 2.2 the tyres are very cold and to take extra care. To be honest I still take care at 2.2 as that just means that they are at warm weather minimum. It does take the guess work out of it.