GoT's world is just too bland to carry an open world """RPG""", which is what Bethesda is known for primarily. Basically one playable race, bland monsters with the only exception being those zombie things and dragons. If there's more I guess I wouldn't know, haven't actually read the books or watched the show in depth. But I have seen some of it. Never really saw anything that captured my interest or anything beyond generic fantasy.
If this is going to a real Bethesda project it would be better to make more of an action game with a focus on story to appeal to normies.
What is generic fantasy? Isn't it high medieval fantasy with 100s of magical monsters etc. GoT is as low magic as it can be, its anything but generic. Technically its humans only Skyrim with only draugr and I guess dragon priests as magical creatures go(and too few dragons). Tactically its war and politics of noble families aside from once in 8k or so years white walker rise.
I played GoT rpg from 2012 recently, deleted it after playing I guess 1/3 of the game; horrible production quality but it tries to capture the essence of what asoiaf's world about.
For 3rd action console RPG GoT; single map open world wouldn't work, Witcher 3's style hub based open world could tho, still it would be a big undertaking with most hubs as big as Witcher 3's Toussaint and the biggest as Novigrad. As far as gameplay goes, we should wait and see KCD first, it will either break the fucking traditional fantasy trope all you guys relying on for a medieval game world to be
fun or won't. Its said to be having big battles also, will be interesting to see...
Hub based can also be made in any old iso style/pillars engine or some mix of 3rd action console rpg and Total War for big battles.
Anyway, bethesda handling any of this would be even worse than how D&D handled the last 3 seasons of the tv show. CDPR wouldn't be interested, they have Witcher already, which has more compatible world for medieval rpgs you would expect and is similar to asoiaf in many ways.
And I would argue that the current story has to be finished for a compelling rpg to be made from its world, which also has to remain somewhat unchanged; the world shouldn't change dramatically like bringing democracy to Westeros or WWs killing everyone. Otherwise it would either be a fan fiction of the current events or too small scale playing around the current events or a prequel which I wouldn't like and the author pretty much covered and is continuing to cover what happened before; the last three centuries in detail.