Having discussed in a few threads what I thought an Axis victory would look like, and revisiting this series (since I consider it to be by far the most realistic take on the trope that I've seen so far), I gotta wonder what the endgame was for the Soviet Union after the Berlin Treaty, both in the minds of the German and Soviet governments (at least, if the war hadn't gone hot again and interrupted that). Because a country where 1.2 million working-age people get shipped off to be worked to death ever year is pretty much in terminal demographic decline. Even discounting the fact that no one's going to want to have kids if there's a good chance they'll lose them to the monthly reaping, there's pretty much no birthrate that can make up for the loss.
Of course, for the Germans it's certainly by design, but I gotta wonder what they'd do once the slave labour supply runs out. Eventually their demand for slaves will affect the production of all the other materials they extract from the Soviets as the terminal decline in its working-age population leads to a forever growing and unsolvable labour shortage. They may have to choose which resources they want/need more of, regardless of their absurd demands for additional tribute as penalty from the Soviets.
And then there's the military divisions who collect the tribute; who are themselves made up of able-bodied, military-age men. With less and less of them, there's even less ability to extract tribute or transport it west. At some point do they go after the soldiers loyal to Molotov's competitors? Sounds dangerous; they're poorly armed but still armed men with nothing to lose. At this point it's probably inevitable that the country collapses into a multi-sided civil war like it did after the Krasnoyarsk bombing in the story, except with many more years of getting cannibalized there's likely far less people around, especially working-age ones. Basically a very empty, geriatric, dead country. Maybe there isn't much fighting besides the initial collapse of central authority, and what people remain just try to survive on their own with very few others around. Either way, collapse seems inevitable. Although for the Soviet leadership, who I imagine are just trying to get through the present without any hope for or ability to plan for the future, do they even get to that point of dismantling their own country? If they're increasingly aware that there's no other way this ends, perhaps many decide to throw in the towel and make for the Iranian or Chinese border.
I recall the author predicting that if the Warm War hadn't ended, the Reich's supply of slave labour would dry up by the 1970s or so, at which point I imagine the collapse of the rump Soviet Union is more or less inevitable. Perhaps not so much a collapse as just... fading out of existence. With no captive Soviet central authority or military to do the dirty work of the reaping for them, and already having a military presence in Vladivostok, I can only assume that the German military would move into the country to capture or exterminate the remaining population themselves. With a full Soviet collapse there's no reason for Germany to continue the pretence of an independent USSR, and my best guess is that they officially annex all remaining Soviet territory, all the way to the Bering Strait.
Really, of all TLs I've seen, I don't think I've ever seen a more depressing place to be than the 1943-1958 era Soviet Union in AANW.