Hodgdon is the only one boasting about their powders. Winchester & IMR don't seem to do any promoting so I haven't heard of any sales pitches from those two since Trailboss. Don't really know if that temperature resistance thing will really make that much difference with levers.
Hodgdon does not now, nor ever has, produced any smokeless powder.
The "IMR" extruded powders are built in Canada, by Merican defense contractor; General Dynamics. All Win/Hodgy ball powder is built in Florida, by the same folks.
"Extreme" powders are that way, due to coatings. However, it is NOT a universal property. It is that way under a specific set of conditions. Dr. Denton Bramwell has done some very good scientific testing on this. Also showing that most of sensitivity comes from heat transfer from a hot chamber, from people cooking their rounds.
From some work done by GD, and getting approval upon it; it would appear that their new generation of ball powders can be every bit as magic.
Darkker is correct about Hodgdon not making any powders, just distributing them. I personally believe that the "extreme" line of powders is only a sales gimmick. If 50 to 75 fps loss of velocity in really cold climes worries somebody, they need to get another hobby. No animal, big or small, is going to notice whether it got hit by a bullet propelled by extreme powder or not. Just my two cents worth and I'm too old and grumpy to debate it.