Many apologies if this has been discussed before (I'm sure it has, but the Search function refuses to cooperate with me this morning), but what would be the impact if the German High Command had taken Napoleon's lesson to heart regarding Russia and General Winter? Let's say Barbaross is launched per OTL, but with winter clothing and other supplies already laid in and ready for distribution when the weather turns colder in September/October. Could a better-prepared German army have taken Moscow, for example?
Germany attack in Poland in 1914/1915 in a heavy blizzard. The lessons were there, the Germans chose to not learn. The logistical commanders told the GHQ that there was not enough ammo, replacement equipment, etc. Hitler went ahead anyway.
To more uniforms only. I have read accounts they did not exist in large enough numbers, I have read accounts it was mostly a distribution issue. But ok, they have them. The offense still bogs down because of low ammo and other supplies. Basically each week in 1941, the amount of supplies in corp level depot declines (i.e. consumption higher than supply). With better uniforms a bit more of Moscow is taken, and the German army defends a good bit better. So take map of max extent of German lines in 1941, and the April 1942 lines around Moscow. The new line is somewhere in between these two lines. Helps Germans not war winner.
Now take the number of men dead or crippled by frost bites, form into light infantry division, Germany has that many more formations in 1942. You will have to research two topics, but if you do, you will have a good feel for this what if.
Extra units(replacement soldiers) probably go to Army group south, and are ground up in Stalingrad. More Russians die in Stalingrad area, but unless it is a huge number of German frostbite losses, it changes little in the big scheme of things. WW2 was not that close by late 1942, so unless Germany has hundreds of thousands of extra soldiers with equipment, it is hard to see a big change to the war. Russia has 599 divisions in this war, the USA had 100 division or so. Germany was 200 to 300 divisions. Saving say 60,000 casualties (2 corp) is not so large in this war. WW2 is so much bigger in scale than wars these days.