Spin-off talk

So as some of you might have heard, there's been a couple rumors suggesting that a House of Cards spin-off could be possible in the near future. Most notably, people are interested in Doug Stamper's background and how his overall story arc could somewhat continue the series.

While I personally believe it's just talk, the idea got me thinking about what a HoC spin-off could be like. What could one be about? Could one be set in the same universe and be even as successful?

I'm going to start this thread by throwing my opinion out there and say I think I would like to see the rise of Garrett Walker before the events of the series. I always thought he was a character I wanted to see more of after his first appearance.

What grew my interest in his unseen moments was an interview with the actor done a few years ago in which Michel Gill (actor of Walker) claimed there was a bit more to Walker in terms of who he sought advice from and why he was such a bully to whom ever agreed to be his VP.

Idk, any thoughts?