1989 is knocking.
Since the CCCP officially dissolved on December 26, 1991 that is not a bad guess. The longer the war goes on the greater the probability Russia faces another collapse. I am starting to think the invasion is turning Russia into a suicide cult on a two year suicide pact. During the first year the Russian military dies. 300,000 conscripts who barely know how to wear their uniforms or hold rifles will not change this. During the second year, the Russian government and economy die next. The Russian economy is dependent on the sale of oil and gas to buy what is needed to run the rest of the economy. Long term Russia is having its global trade cut deep. Even if Russia does not collapse again, the country will be so weakened politically and economically it will be hard to tell the difference.