In past murder cases I also have been interested in the decomposition aspect and how it relates to evidence. I think what makes this case unique though is the nighttime temperatures fell below freezing on many nights around the time and after him being reported as missing.
I have read up on some of the Body Farm studies but I dont recall ever seeing a study of what would happen if about 1/2 of a day was always below freezing. Once frozen, things take awhile to thaw and if the nighttime temps went below freezing every night, then I wonder if decomposition in this case was not nearly progressed as much as we would normally think. There may have not been near as much odor as usual until he was moved South.
Of course that is assuming his body was kept where the outside temperatures affected it. We really dont know that yet I suppose.
For what its worth, below link shows what the temperatures were around the time of his disappearance. High and Low temps included for each day.
https://www.accuweather.com/en/us/colorado-springs/80903/february-weather/327351