Well, you have certainly played an excellent game, but I think that your pocket shows that the "March Madness" issue has not gone away. Granted, you had a pretty easy Blizzard, but still...
I don't think in this case one could speak of "March Madness". This is different now, and I find it justified in this case. The power of the Wehrmacht offensive is more of strategic scale here, and it still packs a huge punch whereas the SHC units seem to be even weaker than usual.
Open the 1942 GC scenario and check the forces on both sides, particularly the Wehrmacht strengths. That is the reference scenario in which a strong March offensive is not credible, but here it is just like the start of the 41 campaign over again.
All that doesn't come as a surprise. On page 5 you can read plenty of comments that already suggested after turn 16 that this game was pretty much done for Tarhunnas. Obviously even the recovery some people have pointed to has not really fruited yet. Even if Tarhunnas prevents the 260VP, his recovery will be so slow that Berlin is out of question unless Axis will play foolish and reckless from now on.
After turn 16, and the huge Moscow pocket with some 500k SHC in there if I recall correctly, Tarhunnas was down to 3M men before winter. That is well below the 4.5-5M mark that usually gives an "average/mediocre" blizzard performance. Even the blizzard penalties were of little use given the whipping that SHC had suffered in the summer campaign. I think this is one of the cases were the swings in initiatives and strengths are more pronounced, and this game was far off the tiny middle path already after turn 6ish. And by turn 17 it was simply an Axis major victory.
The game engine is just not dynamic enough at this point to account for GC courses that are either poorer or better than average, adjusting economy, production, reinforcement schedules or lend-and-lease down or up to the real course. I imagine in this course of events the Reds would have gotten more help from the West, and would also have taken more severe (drafting) measures to gain replacements. But all these parameters are set as if the course was just historical, and Tarhunnas faced tough challenge to recover after turn 16. I think he could well have folded then.