Witr is a confirmed Sunnah and

Q 14: I like to wake up at night to perform a few Rak`ahs (units of Prayer) and I like to perform the Shaf` (two units of Prayer, particularly before the final unit of the odd-number prayer) directly after the `Isha (Night) Prayer and delay the Rak`ah for Witr (Prayer with an odd number of units). Is it permissible to do this or should the two Rak`ahs of Shaf` be connected to the Rak`ah of Witr? Is there a preference?

A: When you finish the voluntary Salah at night, perform one Rak`ah of Witr, because the Prophet said, "Salah during the night should consist of pairs (of Rak`ahs), but if one of you fears morning (is near), they should pray one Rak`ah, which will make their Salah an odd number." (Agreed upon by Al-Bukhari and Muslim) It is better to delay it to the last part of the night if it is easy to do so. If it is not, Witr may be performed at the beginning of the night according to the Hadith Sahih (Hadith that have been transmitted by people known for their uprightness and exactitude; free from eccentricity and blemish) reported from the Prophet (peace be upon him) in this regard. If you offer the Salah at the beginning of the night and delay Witr to the last part of it, there is no harm; in fact this is better according to what the Prophet said, "Make Witr your last Salah at night." (Agreed upon by Al-Bukhari and Muslim) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.