I think the question now is really what the West will do. Ukrainians are now capable at most to enforce the stalemate, and maybe pushing Russians to the border in Kiyv.
Time really benefits Russians with their slow logistics. Even if 40% of Russian military assets were thrown on Ukraine, and they were wiped out to the last, Russia still has resources for 1 more land offensive, and Russian generals will try to not to bungle it as hard as the first one just out of sheer sense of self-preservation.
Ukrainian military assets, and cohesion are getting depleted no question about that.
UAF priority is now to inflict as much damage until summer begins, and to turn as much territorials into real soldiers.
The key is April. Actually, the key is for the Russian to take Mariupol before April.
Why April? April is where their initial conscript contract run out, so on April 1, there are going to be an influx of new conscript and most likely being send to battle like the last batch. Now, knowing what they know, that it was a war going on since Late Feb, would you want to be in that war?
While it is true that Russia have a lot of Troop, 900,000 standing and up to 2 millions reserve is the last conservative estimation. But you also need to remember Russia is one giant piece of landmass, which mean they would also need a lot of station force. That mean for a new rotation, there are only 1 out of 3 ways they could go
1.) The Cheap Skate way, do something like the "Stop-Loss" policy like the American did during Iraq and Afghanistan , extend the contract for the original conscript and have them stay put in the battlefield. Then you don't need to raise a lot of troop to fill the gap
2.) Mobilise the reserve, which is a sensible thing to do, but that mean it takes time to get them up to combat ready level.
3.) Send in the ready to go regular troop, That's the quickest way, but it take defensive power off Russia.
Now, all 3 solution would heavily depends on whether or not the Russia have any strategic gain, which at this point the closest is Mariupol. If they cannot take it before the April 1 rotation, that will present a problem for the Russian. Because assuming the normal Russian was not fed any information on the front line, they would still have know Putin have declare a Special Military Operation (And more or less by banning the word war, everyone would know this is actually a war) Which mean if nothing was gain for the 5 or 6 weeks operation, morale is going to drop. If this is the case, then option 1 and 2 would not cut it, it will most likely end up like the first batch.
Which is realistically the only people Russia can send is their regular. But would Putin willing to risk Russia national security
On the other hand, on the Ukrainian side, the longer they hold out, the longer they will give the Russian some thought about whether or not this war is worth it. Don't get me wrong, Russia sheer combat power trump Ukrainian, so if the Russian do not let go and do this day and night with multiple rotation, then at some point they are going to have the advantage over the Ukrainian. And it would be Ukrainian job to make the Russia reach this point as late as possible and as costly as possible. And force them into a negotiation table.
