To all you engine warmer-uppers, try this: Tomorrow morning, start your car as you normally do, but this time wait about 15 seconds and start gently driving it, and listen carefully to your engine as you do.
When you get home from work that night, drain all of the oil out of your engine, let the car sit overnight with the drain plug out, and then start it up the next morning and drive it gently as you did the day before, again listening carefully to your engine for about a minute. Does it really sound the same as it did the day before? I don't think "lack of oil flow" is that big of a problem in the cold. If it was that much of a problem, I'm not sure you could even turn the engine over.
Your hypothesis is faulty in many ways, but chiefly this: if the problem on a cold morning is that the oil is cold and that it won't be "flowing" to critical engine parts, that holds true whether the engine is idling or moving the vehicle. The only difference is, the oil and all of the metal in the engine will heat up more quickly, expand, or whatever else you want to have happen, much more quickly and efficiently if the engine is gently driven than if the engine is idled. In other words, it's your choice to run the engine for a longer period of time under the conditions you purport, or for much, much less time at slightly higher RPMs.
It says right in my manual to avoid excessive idling, start the car and let it idle about 15 seconds, then drive it gently (RPMs under 2500) until the temp gauge comes up to normal. 204,000 miles, so far so good, in all sorts of Chicago temperatures.
