Here's my task 10 essay. Six minutes to write and two minutes to get the word count down to 132 words.
Score: 5.0.
So it appears that you need 130+ words to get 5.0, with no grammar mistakes. Let check grammar next.
The global average TOEFL speaking score is 19. The Japan average score is 15. For our students who take 4+ months of classes, the average top TOEFL speaking score is 23. Why? Because they don't use templates! If you have a clear voice and practice regularly, you should get 23 consistently too.