The first four book were released a year apart. It took 3 years for fifth book and then 2 years apart for the final two books. Yes, they might be long but released over 10 years doesn’t make them seem that bloated. On the other hand, I agree the plays are way too long. I think for fans, they are great. But for the average person familiar with the stories, i felt it would have been better done in one play.
Compared to angels in America where the plays are 3.5 and 4 hours long, it would be difficult to shorten into one play (although it has been done). It did tour for a year and a half. Most stops seem to be two nights in the beginning so I assume both parts were presented. Later stops in the tour were LA and dc which played a month or more. But maybe others know more about the tour than ibdb has.