There are mixed signals from Ukraine.
If you saw a video I posted yesterday where the Ukraine diplomatic adviser gave to an Indian channel. In that video, the advisor asked for iron-clad guarantees backed up by foreign powers for Ukraine's security and for that Ukraine would sign some neutrality agreement with Russia. BUT in the same interview the advisor also used the term 'for the time being' to not ask for Nato membership. Russia, if you recall, had asked for a permanent agreement of neutrality before the war began--actually just a few days before the war began. Russia asked for more than some for the time being agreement.
Anyway, what Ukraine should fear is that Russia decides to reduce its invasion to eastern and southern parts, consolidates there, use the very considerable Russian ethnic presence, especially in the eastern part, and make the Dnipier River, which is supposed to have only limited crossings, a natural barrier and target the Russian guns on Kiev as blackmail... sort of like North Korea does by targeting Seoul. IF Russia is able to achieve those goals--which are in the realm of possibilities--then Russia will have won the war even if at great cost to itself. I believe in that case Russia will eventually ride out the sanctions.