Witr: is the standing lengthened or not?

Ibrahim says: One night I went to al-Aswad while he was ill. He prayed witr in a state where he was leaning against a man. He recited the qunut supplication and lengthened it so much that I thought he had recited it longer than his usual amount.

Isma'il bin Abd al-Malik says that when Sa'id bin Jubayr led us in witr, he used to stand for as long as it takes to recite a hundred verses.

Ibrahim says that in the qunut of witr one should stand for as long as it takes to recite Surah al-Inshiqaq.

Asim says that Abu Uthman was asked how long Sayyiduna Umar (may Allah be pleased with him) took in the qunut of Fajr. He said: As long as it takes a man to recite a hundred verses.