Russia can win but it will need to expel every Ukie from the areas it controls. Otherwise it will be faced eith an ongoing guerilla war but with high tech weaponry.
90% of the Ukrainian population in polls believes that their victory is inevitable. Vast majority of Ukrainian discourse at this point is clowning the Russians on how stupid and worthless they are. There have been no significant gains by the Russians in the past month, only continual bombardment by HIMARs, despite constant promises and predictions of the imminent defeat of Ukraine by Russian propagandists since day 1.
Meanwhile, Ukraine’s reserves—which include more than a million people at this point—are either already ready or soon will be by the end of this month, which even Russian military observers like the infamous Igor Strelkov says means Russia will ultimately lose the war due to lack of manpower.
Unless Russia calls for WW2 levels of conscription or takes up North Korea’s offer to accept 100,000 NORK soldiers, their loss is inevitable.