As Richard pointed out above, UNLESS the engine, tranny and primary FLUIDS can be brought up to operating temperature so as to drive off any condensing water that has accumulated in these spaces, DO NOT just start the engine and run it at idle for a few minutes. The consequence to this is that the combustion by-products combine with the water to form acids that will attack the metals.
It takes me almost all the way to work (over 20 miles) in the Winter running a combination of highway and surface streets before my engine oil in the reservoir is approaching 200 degF. That fairly high reservoir temp combined with the very hot returning oil from the engine I hope is enough to drive off any water from the engine. The tranny and primary get good and warm, but I am not worried about combustion by-products in those systems.
TQ