This thread is full of ideas for sequels/DLC
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=879660&nt=5&page=1 there havce been some other threads to, like this one
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=886214&page=2 sealing with expansion/DLC/sequel ideas as well
for smaller additional content, Minthara as a companion if you side with the grove is the first stand out for me.
The game has an amazing foundation for adventure module content to reuse systems and assets for whole new stories.
