There is no scenario happen short of starting a hot war with Russia and, very likely, not even then.
And, there is absolutely NO will in this country or in any country in Europe for a NATO war with Russia.
Even 68% of the French oppose the idea.
So, there are two options -- Ukraine surrenders and saves what's left of Ukraine. Or Russia keeps going and takes as much territory as necessary to protect its borders.
You, apparently, however, want to turn Ukraine into Palestine. And, the people in Ukraine don't want that.
Simply blow the bridges to Crimea, sink the ships, and commence the bombardment. There is a scenario for you. Provide Ukraine 10,000 Artillery shells per day out of existing inventories, 1,000 cruise missiles, etc.. There is another scenario.
Bottom line: The West can meter out as much intensity as it wants, through how much we supply. We could surge enough to expel Russian forces in a few months, anytime the mood strikes in earnest.
It is better in the long term that the Russian military be thoroughly demilitarized in the process - so they will likely be strung along they are until bled dry. Putin is a sucker for that - he can’t leave, because this Operation is his baby. After the Russian Military collapses, then the private armies of Putin’s Capos can fight over the scraps left of Russia.