Living much closer to Duluth, MN than Duluth, GA, I have some experience with COLD starting. The answer is engines with fuel injection are so good and efficient, you really don't need to let the engine warm up. Just let the car reach a steady idle after start up (a few seconds is usually enough) and just don't drive like a drag racer until the engine is warmed up. What you are presently doing sounds just fine (I'd say you could go a little higher than 2,000 RPM too).
During cold weather starts, there will be unburned fuel and mosture that works it's way to the engine and the oil. This is why it is especially important to have oil and oil filter changes during cold weather (every 3K miles would be fine with most engines, perhaps you could go a little longer).
Heated seats are a big plus too, if you know what I mean.