todo-skip-archived-categories

todo-skip-archived-categories is a variable defined in `todo-mode.el'.
Its value is

nil

Documentation:
Non-nil to handle categories with only archived items specially.

Sequential category navigation using M-x todo-forward-category
or M-x todo-backward-category skips categories that contain only
archived items. Other commands still recognize these categories.
In Todo Categories mode (M-x todo-show-categories-table) these
categories shown in `todo-archived-only' face and pressing the
category button visits the category in the archive instead of the
todo file.

You can customize this variable.