I am not familiar with this tour, but was able to ski Cobabe Canyon yesterday with a friend who is quite familiar with Powder Mountain. The weather was quite cold and windy with light flurries all day. The 1 to 2 feet of powder that we found in Cobabe was left over from the 27" Christmas Eve storm ... still untracked lines after 4 days
I can honestly say that it was a fantastic experience. The place is quite expansive and it felt like we had it to ourselves all day. Over the course of 4 runs in Cobabe, we passed maybe 3 skiers total. We did see a Powder Mountain Host guiding a group of boarders back there, but we never crossed paths after the initial hike out.
If you are not familiar with Powder, I would recommend utilizing a guide (or hooking up with some locals).