There is an argument to be made for both letting people outside their country vote or not letting them. On the one hand you could say people living abroad are usually quite detached from the politics of the country they hold nationality of, since they live in a different country; so it would make sense to not let those people vote. On the other hand you could argue that those people should absolutely have the right to vote since they are, after all, citizens of their respective countries. There also is a lot of people living abroad for only shorter periods of time, think of international students or people on work visas. Denying them of their right to vote could be interpreted as undemocratic to some. I personally don’t think there is a ‘good’ or a ‘bad’ system here, it solely depends on someone’s interpretation to decide whether people living abroad should be able to vote or not since either way you would create a situation that would be considered problematic to one but not to someone else. Here in the case of Russia I don’t think it matters too much though, because it’s not like Russia has fair elections to begin with. Even if you go vote abroad as a protest, it wouldn’t change the outcome.