If he wasn't stopped.
Ukrane probably depolulated
Western USSR depopulation begining.
Poland Depopulated
Most jews in europe exterminated
The continued use of soviet POWs as workers (death through work)
tens of thousands more homosexuals/disabled/'undesirables' exterminated.
Hundreds of thousands more dead, maybe millions.
Though my statements in this thread are on the softer side, I would say that you are right and I would also say that the question is rather "millions or tens of millions" additionaly deaths.
Seriously, what is with this site than any discussion about the Nazis being slightly different than the epitome of evil OTL brand is viewed as Nazi apologism?
Generally, looking closely, question doesn't ask how "we" here on this forum, people with a more than average knowledge of history, or professional historians would view the Nazis, but their general image. The question is also not how feasible it is that the Nazis take a different path to pursue their genocidal goals and how that would play out.
I translate this to "how important are the special circumstances of the death camps important to the general image of the Nazis". Cynically said, we are dealing rather with a cultural than with a political issue here.
Imagine the rails towards that gate in Auschwitz. I do not need to post a photo. We all see that in our mind's eye as we read it. It is an icon, and a powerful one. In the context of the holocaust, there are other important pictures concerning the issue, but this one trumps it all. How many people you know can name more death camps than this one? How many people you know more about the Holocaust than the death camps, are aware of the several methods and different stations of the exclusion of Jews from society, and ultimately the ways to kill them? How many people you know are directly aware how many groups the Nazis singled out for extermination?
Also, the singularity of the Holocaust, a view I personally take with a grain of salt, heavily relies on the idea of "industrial extermination". If this is taken away from the equasion, the doors are wide open for comparison by numbers. Because - putting people to work until they drop; shooting the population of villages; have special units commit killing sprees....that's not so difficult as to that only Germans can do that.
However, for reasons I mentioned earlier, the Nazis will still eclipse other villains in our minds. With a slightly fuzzier picture of the genocide perpetraded, our fixation on WW2 will remain a bit less focussed on the Holocaust (if the term will become common at all - without the crematories) but more on the military matters. That means, it will be more as it was in the 1950s.