[CT Jack]

If you are not running with a 180 degree thermostat, I would partially block off your radiator when driving in temps below 40. Think of it like this: The wind chill at 30mph on a 20 degree day is equivalent to the rate of heat lost at 0 degrees. Even though you let your engine warm up before driving you are losing a lot of the heat being generated by the engine both in the cooling and lubrication systems. The sludge in the breather is evidence that oil is leaking by the larger than normal internal clearances created by the low operating temperature of the engine and is condensing very rapidly.