Don't fly a drone in ice fog
Commercial aircraft are "de-iced" when flying in harsh winter conditions. There's a reason for this...
Here's what the props on a Mavic look like after a 3 minute flight:
The ice changes the aerodynamics of the prop for sure, and messes with the ability to provide lift. Not to mention the damage that this kind of ice can do to the electronics in the drone.
So after 3 minutes, I landed again :-)