Not sure if it would break the stalemate, but it will break Putin for sure, as then he'll be forced to mobilize more troops to fill the gaps, something he promised and vowed no to do on repeated occasions, so breaking that promise would break any trust the Russians have in him. Putin would be absolutely done after this, with no chance to recover politically.

On the other side, it would also be another sign to normal Russians that the war with Ukraine didn't go as well as they've been told to for 4 years. Ukraine is slowly gaining the initiative also on the battlefield as their counterattacks allow them to make some room, though Russia is still advancing slowly direction the fortress belt with fighting within Konstantynivka.

Russia's biggest issue isn't it's military however, it's it's economy, and especially funds to procure anything. Funds they mostly got from oil exports, which Ukraine is successively shutting down. They can't even sell their bonds anymore:

If this keeps going on then Russia will be forced to end the war with accepting all Ukrainian concessions just so they can get bailed out of their misery by the IMF.