Bolt isn't a great anime, so it shouldn't count towards Naruto's greatness length. But there is a small portion of Bolt that is real. This is the scarlet spring arc and the Mitsuki origin story, both written by Kishimoto himself.
Those portions are still great anime and must-see tv, worthy of being not only watched but rewatched, alongside the actual Bolt movie that Kishimoto wrote.
Preserving these portions while deleting the rest of the Bolt anime is -45 episodes in all. This puts Naruto's length down to a much more manageable 114 episodes (Naruto Kai episodes do tend to be 2-3 times the length of normal anime episodes though, so it's still a very long series.)
Great Anime as a whole is down to 8960 episodes/movies in all. So now my 'over 9,000' anime celebration looks a bit premature. It's just a minor setback, by the end of 2018 we'll be back over 9,000 again.
There's no particular reason why people should be watching Bolt other than for the Scarlet Spring and Mitsuki episodes. (eps 19-23 + ep 39) Nor should Bolt episodes count towards 2018's greatness.
Without Bolt or Pretty Cure, 2018 actually has only had 19 represented franchises so far. 19 great franchises have released new great content this year, only 2 of which are brand new. The fall season should spruce up that number a bit, but it's still a legendary collapse from the year before.
Once 'One Pace' releases its complete fan-edited version of One Piece, I can shrink the length of great anime one more time, but for now this is as sleek as I can make things.