A change in leadership probably won't bring peace any time soon. In the US Nixon ran on a platform that he was going to end the Vietnam War. After trying to step up the war and force North Vietnam into submission, he finally did pull the plug. But that didn't happen until his second term.
I don't expect Putin's replacement to be from the pro-peace faction. The faction who believe the only reason Russia is losing is they didn't go at the war hard enough are in the ascension in Russian politics. It looks like Prigozhin is going to run for president next year. As
@Tiger posted, there is at least one person on Russian TV saying that someone else should replace Putin in next year's election. That's huge in Russia.
It's possible that a Putin replacement will try to step up the war and will then pull the plug when that fails. There are only a few things the Russians can do at this point to escalate: use nuclear weapons, use chemical weapons, try full mobilization. The first two would likely get Russia more isolated than they currently are. I think both China and India have told Putin that they will distance themselves from Russia if they used nuclear weapons and probably chemical weapons too. That leave them with more mobilization, but anybody trying that is going to find out very quickly why Putin didn't do it.
Mass mobilization would be a very bad idea for Russia. The young men who are now not mobilized are keeping the economy afloat. Russia is unusually top heavy in their age brackets. The economy would deteriorate badly if a significant number of the 18-40 age group were drafted. On top of that there are other problems. The draft is very unpopular in Russia and there is already a fair amount of discontent with the war. Mass mobilization could start draft riots which the Kremlin may be unable to put down. Then there is the practical problems of what to do with a lot of new mobiks. They don't have the ability to train them and they don't have the equipment to arm them. With the last wave of mobiks they were getting the ancient rifles in the back of the warehouse that were rusted hulks. The border guards are now armed with WW I rifles because all the automatic rifles were taken by the army.
In the winter battles a lot of mobiks units were going into battle with just a rifle and one clip of ammunition. Nothing else. Russia can eventually spin up production to make more rifles and more ammunition, but they are dependent on China for the chemicals needed to make ammunition and they need to do something to prioritize war production and shut down other industries.
I saw an article, it may have been one posted here, a couple of weeks ago that Russia has completely failed to up production of war goods in many areas because they have a labor shortage. Moscow has demanded increased production, but the war industries are struggling to maintain enough workforce to stay at pre-war production levels. In some cases production is below pre-war levels due to shortages, including labor.
Mass mobilization would make the labor shortage worse.
Russia doesn't have the population to run a large scale war industry and fight a war with high mobilization. The bulk of their excess population are old women. The average life expectancy of a Russian man is in the low 60s, but women can live into their 70s and 80s. To run the factories while the youth are off at war they would need to mobilize the female workforce to be in the factories and most of those would be old women.
If Russia were at threat like they were in the 1940s, the old women might step forward for the war effort and the young men might be willing to go, but there is not that kind of urgency to this war. At the end of the day, this is an optional war for Russia. Putin may have thought that Russia couldn't survive long term without Ukraine inside the tent, and he might be right, but that is a weak selling point for a war now. If the war had been a quick win, Putin would be a hero and people would see Russia as stronger, but Russians don't see the advantages to spilling a lot of blood and treasure now for Ukraine.
Whether Putin gets toppled in next year's elections (may not be possible with his fiddling with the vote) or ousted in a coup, his replacement is likely going to try and get tougher on Ukraine before throwing in the towel. If Russia gets that far. The scenario for Russian civil war ending the Ukraine war is also a possibility. This war has opened up the ethnic tensions in Russia that have been there for centuries. The lid is still on, but an attempt at mass mobilization might blow that lid off.
