Upper wing covered by snow during takeoff roll

[theWings]

Any exception to the rule?

January in northern Scandinavia:

Aircraft deices on departure from an airfield where OAT is -15C with moderate snow. Flies 90min, cruising at FL400. Arrives at destination where OAT is -26C, light snow. 30min turnaround. Plenty of snow on the aircraft but crew tactile check no snow is adhering to the airframe as ice, and depart without deicing.

Completely insane, or operating under some little known but perfectly legal procedures??

Is it possible for both the air and the aircraft to be so cold that frozen precipitation cannot stick to critical surfaces, as a scientifically proven fact?? Doesn't seem right but I'm always ready to be amazed by science!

Would be good to hear the facts from an operator who actually does this, if indeed they exist...