The two definitive biographies on Patrick Henry now, IMO, are (full disclosure, I know them both and the second has become a good friend): Patrick Henry: Champion of Liberty (2017) by Jon Kukla and Patrick Henry: Proclaiming a Revolution (2017) by John Ragosta. In an appendix in his book, John lists all of the children and grandchildren. I don't know of one source that lists beyond that (other than WikiTree), although there is a (volunteer) genealogist at Red Hill (the son of the late and much beloved Edith Poindexter) who tracks all of the known descendants.