Humberto
Relax
A combination of piling more and more resources into Ukraine, a proportion of which will be scraping the barrel, 'popping smoke and declaring victory', and lashing out.
They, imv, do have the raw combat power to take Ukraine east of the Dneipner. However, it would mean stripping the entire Russian military of armour, artillery, and infantry, and combat aircraft, from Vladivostok to Murmansk, and the likelihood of taking material and personnel losses that Russia might take 10 years to recover from.
The question, which I simply don't - and won't pretend to - know the answer to, is whether Putin, and the wider power structures, is prepared to take the gamble of committing that force, and accepting the risk of having a seriously degraded military for the next decade, while the vultures circle....
Hope you are right. Let their enemy fuck themselves up, maybe. And those announcing support to never accept that the Russian governments' actions have any legitimacy. Ukraine will need to pick its battles, even so.