1) Use the block heater for 2-4 hours (on a timer)
2) Put in D and drive gently. You will notice that if you are easy on the gas pedal, then the engine RPM stays constant ie. the TCH is doing its part to warmup the ICE in what it feels is the best way.
I'm doing this now when the morning temps are around freezing, and did it throughout the winter when it was -40.
Works for me, YMMV.