I live in cold ambients as previously stated. Some of y'all might consider it real cold.
I drove tractor-trailer for a number of years professionally although they were all Fuller trannys. I regularly operate 3 different firetrucks and a KW mtce vehicle for work, all have Ally autos. I also regularly operate 4 different firetrucks at my volunteer hall, again all 4 have Ally slushboxes.
I've owned a few different 3/4ton/5er combos over the years, all Chev until this Titan.
But, yeah, maybe what my Titan tranny does when cold is what every auto should do (though I've not experienced it in any of the vehicle's I've driven before).
Funny you should mention fire apparatus....I've spec'd, built, and refurbed more than few for VFDs, DOD, and yep, even one for the National Guard in Maine....haven't seen one yet that didn't have a cozy home inside a station house during the winter😁😁😁😁..... So not really apples to apples...
Not sure if owned the early Duramax/Allison 2000 Series around 2002-3 time frame but if you have we won't have to go into the hard shifting complaints and overheating problems that platform had the first few years of launch.
If you like your T-Stat on your XD man that's great and good for you that it works.
I'm just trying to point out that if someone is in -5 degree weather and a truck has been setting outside all night the shifts ain't gonna be butter smooth it started and the operator takes off in the first couple minutes of starting....to include an Allison wether that be 2000/3000/or 4000 Series or even on the old mechanical AT/HT tranny's....