Again?

The Sovjetunion was a multi cultural country, but Russia itself is 80% Russian and then you have a 4% Taras and 2.2% Ukranians. The rest are at the 1% mark. Most are well within Russian territory. Basically the only place Russia could really loose land is in the Caucasus. So Russia is not going to fragment unless there is a civil war going on.

Russia collapsing would mean Ukraine and very likely Belarus moving towards the EU and NATO. Russian influence in Central Asia would propably be replaced with China and the West would move left again, as Russia stops supporting far right Kremlin parties.