Folks best not bitch too much. They'll stop making these wonderful GoT shows. I really want one about the Conquest & one about Robert's Rebellion.
I highly doubt they stop making them
If a show exists, there will be people who complain that things could have been better.
And i agree with @ill . GRRM's world is a cash cow that they are going to milk every cent they can out of.
Assuming the Dunk & Egg series goes off well, they will delve deeper into GRRMs stories. They could do a show centered around Bloodraven. That kind of coincides with the Dunk & Egg timeline. After that chronologically would be the fallout of summerhall into Robert's rebellion.
There's a ton of old lore they could also make into shows or movies, but that may only appeal to nerds like me.