And this changes things how exactly? The Russian population is not going to replace their rulers. Think about it, Romanians, generally regarded as one of the most oppressed and backwards population in the Soviet block--they were so desperate that they stopped tourists passing through Romania and begged them for contraceptives (banned under the Ceausescu regime); they were as demoralised and impoverished as you can imagine. Ownership of typewriters was controlled by the state and you had to register your machine with the local police station. And yet, they finally rebelled and got rid of the dictator. There is nothing that makes me think Russians are willing to do the same, ever. At the core of it is total disregard for human life and freedom. The state teaches the people that they do not matter and the people do not care for each other and for what will happen to them.
Fair enough, and food for thought. Though one has to wonder how many people refused to respond (they apparently don't publish these numbers), or adjusted their response in accord with what they thought was expected of them.
In short, insignificant number of people refuse to answer, and answers cannot be discarded with "that's not what they really think" because surveys measure how people act in the public. One may very well be against the war in their thoughts, but if they go to a munitions factory every morning and fill shells with explosives all day and in the evenings cheer with neighbors over another strike at Ukrainian cities, then their innermost thoughts matter very little.
Russians have always been reminded that it is better to eat white bread on the shores of the Black Sea than the other way round (black bread on the shores of the White Sea) so I wouldn't trust their answers.
I think it would be better to look at number of volunteers signing a contract with military (there is not enough of them). Because one thing is to support the war in a phone poll and another thing is to take a gun and a bulletproof vest and go support it in real life.