If Charles dies within the next decade then the likelihood is Anne, Edward and Sophie will still be carrying out duties as normal. If it’s later, then maybe Anne will be taking a step back but Edward and Sophie are younger so should still be working and William’s own children will be older.
Presumably once George, Charlotte, and Louis are older, Kate will be able to do more duties as she won’t have young children to prioritise.
I can see Louise and James carrying out duties given they are a prince and princess by birthright, despite not using the titles, and are the children of active working royals. Peter and Zara have never been working royals, and given the difference in the ages (compared to Louise and James) it seems unlikely they would start; they are also further from the crown the more years that go by.
I can’t see Beatrice or Eugenie ever carrying out duties. Andrew, Fergie, Beatrice and Eugenie may get invited to various events and show up for family functions but they seem to be firmly on the Not Working side compared to the Working side of the family.
Harry is unlikely to come back, either through choice or public refusal to accept him (like the public is regarding Andrew). Given his children look likely to grow up in another country and with little or no understanding of the royal family, they won’t have a role either.