You think that the German population would actively resist Nazi policies in any significant manner?
If it involves them being forced to do any number of unpopular and difficult things that, even if they could be achieved, would drastically worsen the quality of their lives, yes. Again, the example of Romania shows that while the coercive pronatalism of Ceaucescu did produce a tick upwards in births, this declined over time despite increasingly coercive measures. How are the Nazis supposed to do better?
Who knows? Maybe an ultra-coercive demographic policy by the Nazi government might be the thing that will bring the regime down.