Well done on finding the book DPG!
A point well raised about the setting change as it is significant and harks back to the comments I made earlier about the stakes and obstacles. A story happens to a specific character in a specific place at a specific time to create a specific set of circumstances that enable an interesting story.
Therefore when specifying such a setting as Russia and a time as the revolution you strait away call the readers attention to the details of the environment, the reader then thinks that it must have been done for a reason. If this is the case what is that reason? Does it help tell the story or detract from it? Does it give the characters a more interesting way to do what they do?
However, since the above has been left out of the most recent draft of the logline this is more of a question to be tackled in view of the treatment/script as appose to the logline.
With a clearer context of the logline at work here, as a pitching tool, it could benefit from a few changes. The latest draft of the logline is "leaner", easier to read and therefore understand but a bit of restructuring is needed to aid in its goal (pun intended...).
For your reader to make sense of who the story is about and what she does perhaps first describe the MC then the introduction of the other woman. I think best to avoid such descriptions as "A new found love is put to the test," because they are too vague to depict in what way the love is put to the test. Better to specify an action done by a character or event that happens to them than a broad description such as this.
My problem with the concept is that if another woman comes along Nadya would care and be greatly bothered by him having an affair.
The husband (according to your descriptions) doesn't really want to be with Nadya, regardless, due to circumstances (society, culture, socioeconomic backgrounds) he proposes and she accepts. If Nadya is a strong and capable woman as you described her then she would be well aware of this and if anything be prepared for it. Presumably she wold fight for her man?
Since you keep iterating the importance of the story focusing on Nadya's emotions, wouldn't her pain be her motivation to do something to fix the pain?
Otherwise I'm just not sure what it is that the story will be about. What does Nadya actually do once she discovers the other woman is back?