"When asked 300 days before presidential elections Russians say they would vote for:
30,2% Putin
2% Prigozhin
2% Navalny
1.3% Zhirinovsky (who is dead)"
https://twitter.com/ABarbashin/status/1663222792605630464
https://russianfield.com/300days
Not a lot, but still higher than other non-Putin candidates (except Prigozhin, who is now dead)
Firstly, many people wouldn't say they'd vote for Navalny -- that's just against the self-preservation instincts.
Secondly, there are many people who are not "in love" with Navalny, his team and personal views, but still think he'd be a much better president than Putin.
I'd personally estimate the count of people here (in Russia) that are neutral/neutral-positive/positive about Navalny at 15-25%. And much higher at hightech giants and top univesities at Moscow/Saint-Petersburg.
The political landscape in Russia is basically this: United Russia, commies and ultranationalists. All of these are pro war with the exception of a single party with a single member in the Duma, which opposes the war due to economic reasons.