As-salamu ‘alaykum wa-rahmatu llahi wa-barakatuh. I have read that we may still perform emphasized sunnah prayers in the Hanbali maddhab despite having many qada’ prayers. Please let me know if there is a limit on how many raka‘at we may perform for Duha and Witr, according to the Hanbalis, if those prayers are allowed in this scenario. Baraka llahu fikum.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The Hanbali scholars are of the view that whoever has many missed prayers must occupy himself with making them up and not with praying the regular Sunnah prayers.

Ibn Qudamah said in Al-Mughni: “One should limit himself to making up for the obligatory prayers [that he had missed], and does not pray supererogatory prayers between them, nor their Sunnahs; because the Prophet missed four prayers on the Day of Al-Khandaq (the battle of the Trench). So he ordered Bilal to call the Iqamah, so he called the Iqamah and he prayed Dhuhr, then he ordered him to call the Iqamah and he prayed Asr, then he ordered him to call the Iqamah and he prayed Maghrib, then he ordered him to call the Iqamah and he prayed ‘Isha. It was not reported that he prayed in between them a Sunnah prayer, because the obligatory prayer is more important, it is better to focus on it.” [End of quote]

As for the number of Dhuha Rak’ahs, the minimum of them according to the Hanbali scholars is two Rak’ahs, and the maximum of them is eight Rak’ahs.

Zaad al-Mustaqna’ reads: “The minimum is two Rak’ahs, and the maximum is eight Rak’ahs.”
According to them, the least of the Witr is one Rak’ah, and the most of it is eleven.

Sharh al-Muntaha reads: (And the least of it); i.e., the Witr, is (one Rak’ah) according to the Hadith of Ibn ‘Umar and Ibn ‘Abbas  attributed to the Prophet “The Witr is one a Rak’ah at the end of the night.” [Muslim], (and most of it); i.e., the Witr, is (eleven) Rak’ahs (Taslim is after every two Rak’ahs and prays Witr one Rak’ah) according to the Hadith of ‘Aa’ishah, may Allaah be pleased with her, that the Prophet used to pray eleven Rak’ahs in the night, and ends them with a single one.”Another wording reads, “He makes Tasleem after every two Rak’ahs, and prays Witr with one Rak’ah.”

For more benefit on how to make up many missed prayers, please refer to Fatawa 86918, 84403, and 83727.

Allah knows best.