It seems we can either;
1) Accept such non-replacement (combined with longevity of an aging populace), and plan for a dwindling/'grey' community over the coming generations, or;
2) Import young foreigners as immigrants and their dependents into our homelands to artificially raise the birth-rate (this is of course the policy followed by our corrupt 'democracies', following their appalling defeat of the Axis), or;
3) Follow the 'blood and soil' policies of sm/fascism, where the White race is encouraged to breed well and proliferate. This will have an eugenic dimension (including euthanasia).

I feel that 1) is too complacent and is essentially suicidal [the Schopenhauerian solution?], while 2) is utterly unacceptable on every level, and is favoured only by capitalists [and our racial enemies] from an economic point of view [and liberals from a sentimental perspective].
So, of the three, 3) is the only tenable solution to a Nietzschean . it has the advantages of being based on Will, Race, and Culture.
It occurs to me that only the great Adolf Hitler has furnished a polity that can really save the Aryan race. Of course, if there are improvements on it, or other options, we must look into them.