I hunted Hot Air canyon in 2005 for late rifle bull. I camped at sheep saddle and took the trail down into hot air and Eagle Creek. I hunted hard for a week looking for a 360 class bull that was in there earlier in the season and could not find him.
There will not be many bulls down there unless there is alot of snow or nasty weather up on the rim.
Your best bet is to hunt off the rim down the ridges into the canyon country, find a good spot before daylight and setup and glass the ridges for feeding/moving elk.
The country down lower does not hold as many elk, but there are some, and it takes alot of scouting to pattern these elk, trust me on this one.
The Chitty burn from last year may be a hot spot. Hot air canyon is very thick and brushy and that is probably why they are doing a burn.
I hiked the full length of Hot Air all the way up to Rose Peak. 2005 was unseasonably hot and a full moon and it was hard hunting down lower, and It took me a week to figure out the elk movement and by that time the hunt was over, I am waitng patiently for my next Unit 27 tag.
Be physically prepared. Unit 27 can kick your butt in a hurry, but the possibility of a good bull is good. Good luck!