Much derision has greeted Putin's claim that nothing has changed in Ukraine and everything is going according to plan. The point being that in reality he has suffered severe setbacks in the Kharkiv region and will likely see the same in Kherson. However it's worthwhile looking carefully at Putin's remarks following the Ukraine counter offensive
There’s no change to the plan...the liberation of the whole Donbas...Despite attempted counter-offensive by Ukraine’s army, [Russia’s] offensive in Donbas continues. We’re gradually occupying more & more territory.
Given this interpretation he is technically correct. Neither Kharkiv nor Kherson nor Zaporizhzhia are part of the Donbas. In fact Izium is also not part of the Donbas though it is a gateway city. So if his plan is the "liberation" of the Donbas, technically losing these other parts does not negate this plan although it certainly can't make retaining the Donbas any easier.
Also technically his remark about gradually occupying more and more territory is true if he is referring to Donbas. The going has been excruciatingly slow after taking Lysychansk but what little progress he has made has been in extending his army's occupation of the Donbas and so far Ukraine has had no significant success at reversing this.
If you think about this from Putin's standpoint this strategy would in fact be his best option for now. While it seems clear now that Russia does not have the resources, human or otherwise, to occupy all of Ukraine. It very likely does have enough to defend the Donbas. This is also the area of greatest support for Russia although it is not clear how much.
Limiting his goals only to the Donbas also buys him more time as it is unlikely that Ukraine will take back the Donbas this year or even seriously attempt it. Liberating Kherson and possibly Zaporizhzhia is probably the most they can expect to do. Thus he may have until next Spring to figure out how to try to protect his claim to the Donbas. Meanwhile, he can claim that the actions in other parts of Ukraine were merely intended to wear down and reduce the strength of the Ukrainian army to make his occupation of the Donbas more secure.
If this is his plan, then Putin's real political trouble will only begin whenever Ukraine successfully retakes a significant chunk of the Donbas. (Taking back a village here or there will simply be viewed as part of the fog of war). An example of this would be if Ukraine were able to regain control of Lysychansk or even Severodonetsk. Of course the final straw would be if it succeeded in taking back Crimea. But we still have a long ways to go before Ukraine is likely able to prosecute these goals so at least until then, Putin has some cover.