So OP is proposing a Gulag style situation? Given the death rates of the OTL Ghettos, Gulags, and labor concentration camps we're going to see just about ever horror of the Holocaust except for gas chambers and Einsatzgruppen murder squads. Of course given Nazi anti-semitic and -communist ideology COIN type operations will probably still result in many many Yugoslav type massacres. Nazism will be viewed as probably just as evil, as the gas chamber aspect and Einsatzgruppen trials aren't known about ITTL, but the horrific nature of the regime and mass starvation and extermination through labor aspects would still happen. At a certain point the horror of the Nazis overloads the sense of outrage, so I don't think TTL Allied world would be any less horrified/outraged by what they find. There would just be more Jews left alive at the end, both within the USSR and within Europe as a whole to be then able to emigrate to either the US or Israel. I guess the question is where all the extra survivors end up ITTL and if the Nazis put as much effort into rounding up Jews in their area of control without a planned genocide. More Jews if not deported from say France, the Netherlands, Belgium, Denmark, Italy, and Hungary among others could well stay in their home country and just live their lives without the disruption of being rounded up and mass murdered. I'd say there is a chance for Jewish life within Europe to continue IF Jews aren't hunted down and deported from all over Europe, including zones outside their control. Romania for instance conducted it's own separate Holocaust, but then stopped (or at least slowed it down) from 1942 on, so without the Nazis demanding Romania turn over their Jews in 1944, their Jewish population could be much larger and potentially stay in place once the iron curtain falls on them.