It ain't broke, so stop trying to 'fix' it.
I honestly don't remember and my solution is "try both for a little bit while maintaining control of the car".
now in the winter you can sometimes do better than this by fixing the temperature differential itself. you can either lower the windows or cool the entire interior by blowing air with no heat. in reality, most people don't actually want to drive around in the winter with windows down or no heat, so the best tolerable option is usually to do as above: turn on AC and heat.
in the summer you can also get fogging on the outside of the windows. just use your wipers for this.
After reading this I am still not sure which one to use. They seem to both work.
When I get in the car in the morning, the air is already cold. No amount of more cold air from the vents will clear that. What's making it fog up, is the moisture I'm exhaling. More cold air is not going to fix that unless I drive with all windows down. So the only reasonable option since AC don't work at low temperature, is waiting for the car to heat up.
(Warm dry air evaporates water that's condensing on cold surfaces. That's very far from rocket science.)
Two: You are making a false choice: Automatic settings need not replace manual ones. Essentially what we are talking about is a spot on the dial that says "auto" which you are free to not use, much like headlight controls on higher end cars.
Well, they worked fine, but my A/C just went out, so getting dehumidified air is a problem these days.
Sure, but the marketing department had to fill a few blanks in the "bad weather options pack" (optional but casually installed on all cars in production that will be available in the next six-eight months) for a mere US$ 3,000:
1) self-learning wipers (using AI to set automatically an appropriate wiping speed, including economode, that only wipes the right side of the windscreen when you make a free turn on right at a traffic light)
2) intelligent defrost (computing the correct defrost temperature through analysis of real-time satellite heat maps)
3) heated and ventilated mats (that can dry your wet shoes and lower half of trousers independently from heating/confitioning settings)
Dry hot air to heat the windshield above the dew point avoids the "damned if you do, damned if you don't" choice of cold dry air to keep the inside from fogging up versus hot humid air to keep the outside from fogging up.
It's not a matter of temperature sensing on the windshield, but humidity sensing in the cabin air.