So, you want a plan that neither side wants, neither side could trust, and at least one side realistically will never sign until a major change in its political administration.
That is the definition of wishful thinking, not stability.
Except that neither of the actual involved sides thinks this way *at all*, i'm not even sure most naive of Western European politicians would think it realistic. That you, a distant and ill informed observer would wish so, matters nothing to either side.
For Ukraine, it's about keeping de facto independence, for Russia, it's about getting Ukraine into its "Imperial restoration project", "Russian world" or whatever one wants it called, either way to the point that Ukraine would either become a part of Russia, its close ally, or at least remain open to future Russian attempts to make it so by whatever means Russia feels like using.
The small strip of land is the hook, not the prize Russia wants, if Russia would manage to get it, it would instantly start working on setting up another hook to reel the rest of Ukraine with.
It's not the winning cities that's bad for Russia, it's the price Russia pays for winning even small cities that's a bad thing for Russia, and it's going to be a catastrophic thing for Russia if it keeps winning more cities at such pricing rate.
