We'll probably never know the actual numbers, and speculating on approval ratings without actually being in the country and talking to people is just that; speculation.
Though in the same vein it's difficult to take the word of 'native Russians' at face value since the ones we typically interact here and elsewhere with seem completely on board with the 'It was fine that we Bombed a Maternity Ward, funneled Tens of Thousands of Civilians into Russia and executed hundreds more because of those six hundred or so Nazis that may or may not hold any actual political influence in a country of 40m people' sort of mentality.