Told you before I do not know what will happen only what it involves.

Winner ends up with the most rivermouths to the Black Sea, extending its reach from across the entire present Ukrainian Sea of Asov northern shoreline from the top of the Crimean Peninsula.
then an even bigger winner if it can control or at least find a natural border on the Dniper.

What must the Ukraine give up for peace?

Crimea is not historically Ukrainian yet has internationally acknowledged sovereignty via Ukrainian independence from the Soviet Union.

I expect the importance of it and the status of Sevastopol and a Russian Federal City with lots of military facilities and Russian military history will not become Ukrainian.
It is inconceivable to me that will be part of a post treaty Ukraine. How many Sea of Asov and Black Sea ports Russia ends up with is keeping eyes on the prize.

Best outcome IMO is Ukraine keeps the Dniper and Black Sea to the beginning of the Crimea and as much of its Asov coastline it can, though I am not optimistic here

From such point It is important to know this is where Russians and Ukrainians met to work in an industrial heartland made possible by these rivers

They are populated by ethnic Russians who see being de facto Russian as their preferred outcome and who have an Orange Revolution history with their countrymates.

So Ukraine keeps its Dniper River basin and Black Sea coastline to the Crimean border and from there up ????

Ukraine will\will not not be allowed to join Nato?????

No weapons domiciled there that could reach Russia????

Lots of important bones for the big dogs to growl over and I have no idea how it will end

Don't think bigger war will break out if things fall through...

Bigger sanctions and likely more military support and action until one side cannot endure any longer.

If writing ever becomes work I think I'm going to have to stop