Before he died from Omicron (despite being 8 times vaccinated with Russia's Sputnik V, or maybe because of it), Zhirinovsky offered disgruntled Americans to immigrate to Russia. It wasn't a serious proposition, like most of Zhirinovsky ever said in public, but anyway you know where he offered them to settle? Well why, in the fucking Siberia. But all this was just his typical clowning anyway.

Proto-Azov guys once talked about retaking Europe for "white races" (that's multiple, an old style classification). They don't do it publicly anymore, but I think their plan was supposedly like what ISIS tried - have like-minded people from other countries immigrate to a future "Social-National" Ukraine before making their own revolutions (a global jihad in the case of IS, "the final crusade" with the Social-Nationalists).

From where?

Taking all of Ukraine (and all of Ukrainians) would increase Russian population by almost 1/3, and the Slavic share massively, but only in a short term because they suffer the very same problems (from just not breeding to rampant alcoholism, drug abuse, and AIDS - over 1% of all Russians have AIDS).

Yes, I know only Australia in the entire world actually welcomes the emigrating South Africans. But there is not many of the Afrikaners anyway (less than 3 million in SA).