PA-46 corporate pilot reported an engine failure with smoke under the cowling during cruise flight. The pilot drifted down and diverted to a close airport and landed safely without damage or injury.

Narrative

Two souls on board. Engine suddenly and catastrophically failed at 20;000 feet. No prior warning or indication. [Requested Priority] with ATC. Started descent. Temp was -20C at time; clear skies. Due to engine failure; cabin began to depressurize. At 16;000 feet noticed smoke coming from top of cowling and could smell something burning. Didn't know source but assumed we might have a fire. Fuel and mags shut off. Rate of descent was increased. Windshield fogged up on descent either from rapid change in temperature or hot smoke hitting cold windshield causing it to fog. Even with reduced visibility from fogged windshield; landed safely; without any air frame damage; on Runway XX at ZZZ. Cell phones were not working on landing; but started to function after about 15 minutes on ground. Made call to ATC to verify we were on ground safely as soon as cell service was working. Law enforcement personnel arrived shortly to help push plane to parking space. After inspection; it was clear there was no fire. The assumption is that hot oil from failed engine cased the smoke; which contributed to the smell of something burning and perhaps the fogged windshield. In summary; sudden engine failure at 20;000; [requested priority]; descent to uneventful landing on runway at ZZZ. No injuries to people; no damage to air frame; no indication of fire; no damage to facilities on the ground. Suggest that CFI's work more with students in how to make rapid emergency descents even at night or in IFR conditions. This safe outcome had a higher chance of success due to perfect weather conditions. Had the problem occurred at night or with low ceilings the outcome might have been less successful.