A Song of Ice and Fire author George R.R. Martin has said he's written 1,100 pages of next book The Winds of Winter, the same amount he'd written as of December 2022, while also revealing there are eight Game of Thrones spin-off shows being worked on.
Why not hire some people to help write it?
He has plenty enough money and could provide as much input as he likes and actually see the books get finished before he dies.