I've love to see more TW and GoT muses. Have you thought of checking out dramadramaduck? It seems to fit in with all of your requirements.

It also allows you to stay in your world, letting you go through canon, if you choose. The nice thing is that, if you want, it's even possible to derail it.

We have a test drive meme here, if you're interested. I'll keep an eye out for you :). If you decide on testing a TW character, I have a Scott I play around with sometimes I'd like to use to thread with you.