Eventually, I think the economic collapse will cause the country to break up into smaller states. It already happened with USSR. In long term perspective, this might improve the situation with human rights. And that’s something that can be accelerated with international economic sanctions.

But I’m not sure this gonna help Navalny. For one, I don’t think he has enough time left. Another thing, when soviet forces retreated from western parts of the country in 1941, they killed hostages instead of releasing them: https://en.wikipedia.org/wiki/NKVD_prisoner_massacres

full economic collapse happened in Venezuela and it didn't loosen the authoritarian grip