Russia been trying to sustain until Trump takes office with the idea that he will help them negotiate a "win" in Ukraine where they keep a significant portion of territory but otherwise withdraw troops, etc. One way or another -- regardless of whether the US cuts off aid -- they have to end the war soon. It's just a question of how favorable the terms are to them or not.
They're on a clock because they are running out of people and money. This is a biased article but concisely explains their financial situation --
Putin’s cash crunch
They have a number of funds and options to cover their issues, but all of them are near depleted, and they can't just "print rubles". Their currency is so unstable that they've suspended exchanges until 2025 to prevent potential bank runs or other panics.
As for people, they've lost about 700k troops (injured + killed) and are struggling massively to sustain their operation:
Given all of the above, I expect Russia to withdraw by June 2025 and for them to keep Crimea + some of their other territorial gains but not all. Most of the negotiations are likely to center around rearming Ukraine to prevent future Russian aggression.