There have been mutterings about a putsch almost from the beginnning of the war.
The parallel is what happened to Kruschev in 1964 after the Bay of Pigs eyeball to eyeball confrontation with President Kennedy. Kruschev was deposed and replaced by Leonid Brezhnev. He went into retirement with a pension and lived until 1971.
Hopefully this is what will happen to Putin, although he may well not need a pension as he is a very wealthy man.
Mind you Leonid Brezhniv was an old school communist leader, under him the Russian economy shrank, there were food shortages and the country slid technically well behind other countries. Corruption became emdemic, although a group of people around Brezhnev, known as the Nomenklatura never lacked anything. He was in power for 18 years.
So what comes after Putin, politically and economically may be no better than what we have now, or even worse, but they would almost without doubt, end the war.