Alta's aren't bothered by temps into the 20s, I just finished the 24hrs of starvation ridge and we had night temps in the 20s, with no loss of performance.
Hope that answers your questions about cold.
That's some awesome trails there, nice mix of tight tracks and more open forest. But as you say, likely the last warm sorta snow free day of this season.
Thanks for sharing!
It was cold, but I think the length of the laps at starvation ridge was what saved us, there was adequate time to charge 2 bikes at a time. Also, our team consisted of 4 A packs and 2 R packs.