Most of the Porsche guys in Edmonton use ow40 , waterless coolant and don't idle the car for longer than it takes to be able to see out the windows enough to drive away .

 

These all good points. My car gets 60 to 120 seconds, then I slowly drive off and take it easy until warm. (to the frustration of the people behind me)
flat6 doesn't list a heater any longer. I may just configure my own with the 'pad' heater I've seen.