Not only is Every Page is Page One a viable way to tackle a large and complex subject, it is the only way to tackle the truly large and complex.
People regularly tell me that Every Page is Page One is fine for small simple stuff, but it won’t work for large and complex subjects. Actually, it is just the opposite. The book model will work okay for small and simple stuff, but it falls down completely when you are dealing with a large and complex information set. When things get really big and really complex, only an Every Page is Page One approach will work.
Confusion on this point is understandable. If you look at Every Page is Page One simply as a prescription for individual topics, then you will necessarily see it as dealing only with small subjects, since each Every Page is Page One topic by itself serves a specific and limited purpose.