It's a question whether Russia needs to move more Russians back into the Caucusus unless they can reverse their current severe population decline. Like Japan and most of Europe, Russian births are far below maintenance rate.
Not that far. The birth rate presently is 1.58 and rising (from a low of 1.2). The male death rate is also now 59.5 up from 54. Abortions after 12 weeks are banned and there is a push for a full ban. Furthermore, Cossak families are very traditional and tend to be big.