Depends on how comfortable you are writing HTML. Depending on the nature of the Knowledge article you may want to look into Micro sites instead, that would give you more flexibility on how to display information.
If it needs to stay a KB one thing I do on my long articles is to add collapsible sections. It still involves changing the HTML for the article but is not to difficult.
Doing that looks like this on the portal:
Not very interactive but it does make long articles easier to navigate.
