I use a spray for this kind of job. Nothing fancy in it, mostly glycerin. The difference is quite noticeable, to the point that sometimes I breath out towards the very cold glass and it doesn't fog up, or if it does, the fog clears very quickly.

When I had a 1.9TDI I used to start it and leave it on my drive until it had warmed up sufficiently to clear the ICE, snow, mist etc... usually about 5 mins..... .

:( Definitely not a good idea - if someone spots your car idling on the drive it's a work of seconds to jump in and drive off! Insurers will not pay for a car stolen in this way. Similar to leaving your keys in the car when you go to pay for fuel.

Just turn the heat right up, air con on and all of the air aimed at the windscreen, the evaporator will cool and dry the air and the heater matrix will reheat the dry air which is the perfect combination.

IIRC the air conditioning is held off below an ambient of 5 degrees C to prevent the refrigerant overcondensing and ice forming on the evaporator.

I find putting the recirc on also helps (as long as the A/C compressor is running) as you are recycling the dried air in the cabin and not dragging damp air in from outside. It usually only takes 2 or 3 minutes to start demisting the screen to a point where you can drive away safely.

Putting recirculation on is a sure way of catching your breath's moisture in. Leave the thing on outside air and lower a window for an inch for the first 1-2 minutes, if it's that bad.

Cold air can hold very little moisture anyway. That's why we freeze dry fruit and other stuff, and why you only get dew when it's cold.

To be honest, when driving 1up I never felt the need to use the blower at full windshield for more than a couple seconds at a time, and for ice I use a spray that melts everything off in seconds.

The mosture in the incoming fresh air will be greater than the moisture you get as you exhale. This will only work if the refrigeration circuit is actually running. And the car will warm up quicker as well with the recirc + A/C running.

Foggy/ misty air is more or less at saturation point (100%R.H.) so there is still a decent amount of moisture in the air even when it's very cold out.

I would have to disagree with dstev, the air you exhale will have significantly more mositure content than the air mositure during the winter. Mositure content in air can be defined using the dew point of the air (this is the temperature at which water vapour in the air will condense out as water). The dew point of the air, and hence the amount of water vapour contained, can only be as high as the actual air temperature. Hence it the air temperature is 2oC then it can only have a dew point of 2oC or less. This means water will only condense on a surface with a temperature of 2oC or less. Hence on a cold winters morning the water vapour in air will be low. In comparison the air coming from you as you exhale will be significantly warmer and since it comes from a damp place (your lungs) it will contain alot of water vapour (assuming it is body temperature then it will have a dew point up to 36oC). This is why when it is very cold you can see your breath, it is the water vapour condensing as the air you exhales cools to below its dew point (also if you breath on a cold surface it will mist up). Hence on a cold day you want to get as much of the outside air (of low dew point) into the car and get your exhaled air (high dew point) out of the car as quick as possible.