It can't go much beyond a year longer as an active conflict like it is now. Either the West loses their interest and pulls their support which cripples the Ukrainians, or Putin runs out of the necessary equipment to stop the Ukrainians. The loss rate of the heavy weapons and precision munitions on the Russian side is unsustainable over much more than a year. And that doesn't even count the human cost on their side (not that Putin gives two shits about that). It either ends with Ukraine negotiating when the West gets tired (I see that in another election cycle), when the Russian military/industrial capacity to keep up with losses fails (I see that in less than 12 months), or when Russia escalates using nuclear weapons (I see that in six months or less when Ukraine takes Kherson and then puts Russia's Crimean positions under their fire control). All three of those occur well before his contract is up.