With today's engines, there is no need for warm up at regular, decent temperatures. Different alloys, different oils, much lower tolerances, are making a difference. Nowadays all manufactures recommend to warm up the engine while driving and they recommend against idling. The engine warms up much faster when driving, thus getting in a closed loop mode much faster. This translates into a much better mpg rate, longer cat life, lower pollution. longer engine life. The engine will be in an open look till it gets to a proper running temperature.
However, at the crazy -30s we have been getting lately, I do give it a few minutes (2-3, tops) without any load to make sure all the parts are well lubricated. Don't run it hard for the first few miles and you are set