Fiqh-us-Sunnah Volume 2, Supererogatory Prayer, Fiqh 2.029.

There is no particular sunnah regarding the recitation during salat at-tarawih. It is related that some people of the early generations would pray with two hundred ‘ayyahs or so and the people would be leaning on staffs due to the protracted standing during the salah. They would not leave their prayers until shortly before dawn and some of them would rush their servants to prepare food for them fearing that dawn may break soon. They would recite al-Baqarah in eight rak’at and if they would complete it in twelve rak’at, they would consider their prayers to have been very short.

Ibn Qudamah says: “Ahmad said: ‘Recite of the Qur’an what is easy for the people and do not be hard upon them, especially during the short nights [i.e. during the summer].'”

[On the same subject], Al-Qadi says: ‘It is not preferred to recite less than the entire Qur’an during the month: in this way, the people will be able to hear the whole Qur’an. Do not recite more than one reading of the Qur’an as this may be hard upon the people. [While reciting], consideration should be given to the condition of the people. If the people concur that they would prefer a long recital, that would be best.’

Likewise, Abu Zharr said: ‘We prayed with the Prophet sallallahu alehi wasallam until we feared that we would miss the pre-dawn meal. And the imam would recite two hundred ‘ayyahs.'”