Putin's approval rating is at 70% [0]. From [1] (referring to the invasion of Crimea):
> President Putin's approval rating among the Russian public increased by nearly 10% since the crisis began, up to 71.6%, the highest in three years, according to a poll conducted by the All-Russian Center for Public Opinion Research, released on 19 March.[346] Additionally, the same poll showed that more than 90% of Russians supported unification with the Crimean Republic
So it looks to me that most Russians supported the Crimea invasion. Why would it be different now? I find it hard to believe that if Russia hadn't found such a stubborn resistance and would've been able to annex Ucrania quickly, which was what the Russian government thought would happen, in five years all the polls wouldn't show Russians supporting the invasion.
[0] https://www.statista.com/statistics/896181/putin-approval-ra...
[1] https://en.m.wikipedia.org/wiki/Annexation_of_Crimea_by_the_...