This article entails as detailed of an analysis as anyone can provide as to where things are headed: Russian Offensive Campaign Assessment, February 28, 2022 | Institute for the Study of War (understandingwar.org)
There are reasons unfortunately to be skeptical that the UKR will be able to hold out, especially in an indiscriminate onslaught of artillery and airstrikes. I think the three things that UKR will need to go in their favor are 1) for Russian soldiers to continue quitting, 2) for logistics to not be able to sustain a long offensive, and 3) for the newly delivered fighters from the EU to prevent Russia from gaining air superiority/supremacy.
There are reasons unfortunately to be skeptical that the UKR will be able to hold out, especially in an indiscriminate onslaught of artillery and airstrikes. I think the three things that UKR will need to go in their favor are 1) for Russian soldiers to continue quitting, 2) for logistics to not be able to sustain a long offensive, and 3) for the newly delivered fighters from the EU to prevent Russia from gaining air superiority/supremacy.