Here's what's happening - it's not a 'fault', it's physics. (note the OP's car has air con)
When air conditioning operates, even in this colder weather, it reduces the amount of water vapour that can remain in the air (air con cools the incoming air to a low temperature, dehumidifying it in the process, and then rewarms it to the required temperature -- a process called 'conditioning', hence the name). As the incoming air is cooled (even in winter), that water vapour condenses into water droplets on the chiller unit (a cold radiator inside the heating/ventilating unit inside the car). Eventually, when enough condensate forms and the condensation 'beads' are big enough, they drop from the chiller into the bottom of the plastic heater unit casing and flow to a drain tube that lets it out under the car. (With air con in buildings, the same condensate forms - look under a wall-mounted air con unit in a restaurant for example and you can see the white plastic pipe used to drain this away outside. Larger building systems collect the condensate and pump it out using pipes above the ceiling)
When you stop the car and leave it parked, there is still dampness left on that chiller unit (like there's still condensation on your empty beer or Coke glass after you finish the drink)
What you are seeing is that residual water inside the chiller/heater unit evaporating back into the air inside the car, helped by the left over heat in the heater matrix (which is hot even if the controls are set to 'cold'), and then condensing on the windscreen - in winter it happens while the car is parked, but it can do this in summer too, often steaming up the car when you start up.
The cure is to turn the air con off (or, with climate control, selecting 'eco' [or the snowflake sysmbol] which stops the chiller from operating) for the last few miles / 15 minutes of your journey, and to be sure the blower fan is on. During this time the last water can drain away or evaporate into the air being blown through the car (and be displaced by more air as you continue to drive) before you reach home, and all will stay clear for the morning. It is important to note that you must not have the system on recirculate at this time as you need to be letting out that 'damp' air and replacing it with 'dry' air as you drive those last few miles.
If you only drive short journeys, in winter, after demisting is done, select 'eco' as soon as you can otherwise you won't give enough time to dry the system out.
With the manual air con system (with control knobs, not push buttons), setting the air flow control to the 'floor' setting when parking can help too, because the condensation-laden air cannot (so easily) rise to the screen. (Even without the fan running, natural convection will move air through the system and into the car)
In passing, it's leaving the system 'damp' that leads to the horrible smells you can get from car air con systems. Turning the chiller off for the last part of the journey (as above) will help prevent this.
End of physics lesson
Pete
