Gosh, maybe... ! Based on the events of the 20th century: When it comes to Russia, nothing is impossible! Is it as "empty" in the Eastern part of Russia as it looks on the map? There are a few large cities in Eastern Russia, aren't there? I thought it was (or at least had been) a conscious strategy in Russia to try to populate the Eastern part of the country.
But if it really is very empty, then I guess it isn't inconcievable that China might be glancing in that direction since they have too many people in their country...They've been really shrewd in how they gone about ensuring their own energy supplies for example. So maybe they'll start looking at getting more "lebensraum"....If there is unused agricultural land, then someone will want it.
But if Chinese people move into Russia, isn't it more feasible that they become Russians (by nationality and language) rather than the borders changing and the land becoming Chinese?
Anyway, I wouldn't panic about the extinction of Russia just yet... Russian is the biggest native language on the European continent!
PS - As for Caucasus; It wouldn't surprise me if many Russians think that whole area is more trouble than it is worth. That may be true from an national economic perspective as well. I don't fully understand the situation; I have understood that Chechnya is increasingly "Islamized" by Kadirov, with the good knowledge of Moscow, and that most of the problems are now coming from Dagestan.
Well, they are Russian citizens with a secular education and the same rights as anyone else in the RF, right? So if they do not enjoy the lifestyle in the Caucasus, they can move elsewhere in Russia and assimilate. Many women DO like Islamic life though. It's very narrow minded to call all Moslem women "slaves". Plenty of Moslem women in Europe keep up the Islamic lifestyle completely of their free will and are perfectly competent to make an educated choice about how they prefer to live.
The women in the Caucasus can choose a traditional lifestyle or a modern lifestyle elesewhere in Russia, depending on their preference. Why would you call them oppressed? Probably, their biggest problems have to do with personal finances, not with how to deal with their culture/religion.