Which is better: to limit oneself to reciting Surat Al-Ikhlas in the Witr prayer and then supplicating, or to recite other surahs with it, for one who wakes up a short time before Fajr?

It is best for a Muslim to occupy their time as much as possible with supererogatory prayers, because they are superior to reciting the Qur'an and all other forms of remembrance (dhikr) and supplications (du'a), as they encompass recitation, remembrance, supplication, and physical acts. Ibn Taymiyyah said: "Prayer is superior" to recitation and remembrance. It is sunnah for one who performs Witr prayer with three rak'ahs to recite Surah Al-A'la in the first, Surah Al-Kafirun in the second, and Surah Al-Ikhlas in the third.