At what point does Putin decide enough is enough?

If you believe everything the Ukrainian government says, the Russians have lost so many thousands of troops, so many hundreds of tanks and armoured personnel carriers, and also fighter aircraft and helicopters, you wonder how Russia can go on fighting in Ukraine. But Putin's pain threshold seems to be so high that I can almost imagine him saying to his army chief of staff, "don't bore me with statistics, just get the job done". But he knows how badly things are going because he has authorised the recruitment of Madmax Syrian mercenaries to be paid large sums to come and fight in Ukraine. So much for the great Russian army. Let us hope that these Syrian baddies, along with the hideous Wagner Group of private killers also hired by the Kremlin's military chiefs to help out in Ukraine, meet the same fate as their Russian counterparts. By the time they have finished sorting out the Russians, Syrians and Wagner militia, the Ukrainian armed forces will be looking more and more like a Nato army. Trained and equipped by the western alliance, the Ukrainians are showing Putin every day that if he ever were to consider taking on Nato, he would without question face a humiliating defeat. It's for this reason that I am hopeful that Putin might just say to himself enough is enough and go for a peace deal. Provided he can claim to his fellow Russians that he has come out the victor. He will no doubt claim that even if the Russian invading troops are driven from Ukraine.