I was surprised I hadn't read this - I've read so much ABOUT it.

Duality and oneness are the themes - the most upfront duality is how gender works on Winter, but there's also the differences in how the main societies function and are governed with openness/decentralized/feudal vs closed/centralized/communal.

The political intrigues that drive our protagonist across societies and from civilization into wilderness are gripping - and then it turns into an endurance adventure.

I'm probably going to reread this in a few years to see if I notice more.