What place did you come in? Just kidding. I've got to admit if I had not lived through and run through those winters 40+ years ago I would not think this was possible. I bought a full face mask last year...every so often it has gotten cold enough to cause my cheeks to sting...usually due to WC not just the temp alone...it was pretty cheap and I used it a couple of times and it was hardly worth the discomfort. If it had been 30 below it probably would not give me the skin protection I need although I did not have some fancy mask back in the olden days...
There were two comments in the story (Runners World on line) that called the participants out for being stupid and the chances they were taking unnecessary. Of course they were blasted for being callous and stupid...actually I don't think they were out of line for what they said...well maybe using stupid was harsh, but even if you believe in this type of event you should be able to understand why people would think you were crazy.
An ultra in the best of weather is an insane event although a part of me would love to run a trail race of some sort. My theory is my horrible foot dragging uneven stride would not slow me down on a path that twists and turns and goes up and down...although after reading about the almost record holder from Dec for over 60 tripping and hurting his knee I think it would be best not to get on too rough a trail...he said as much. He knew that course and it sounded like he would never run it again.
The thing is at our age falls can be a big issue.
Good luck up there.