A "victory" for Ukraine would be if and when the Russian cannot take this beating any longer. The Ukrainian armed forces have the initiative right now and will not be interested in any negotiations. The Russians might want to drag this into a war of attrition again. The Ukrainians cannot be successful in a slugger fest and they will most likely loose the initiative if they are allowing themselves to do it.
There is a quite interesting development in Kherson right now. Are the Russians retreating or are they trying to set a trap to drag the Ukrainians into a costly battle of Kherson
Beating is an exaggeration,as we don't know the amount of the Russian losses: on 18 October Ukranews said that the Russians had lost 2,548 tanks, while Oryx (using the same sources ) said that it was 1100 tanks .
It is possible that the Russians have decided to retreat to have a smaller front that can be more easily defended ,as they have a smaller manpower than the Ukrainians .
Retreat is not defeat .
Who of both can sustain a war of attrition and how long ?
This will decided not only by what's happening on the front,but also by political, economic and military factors .