Is it permissible to make up more than one Witr prayer in a single day when making up missed prayers, and is it valid to make up the Witr prayer days after it was missed?

If there are outstanding obligatory prayers (fara'id) to be made up, one must begin by performing them before engaging in supererogatory prayers (nawafil). This is because a person who has missed obligatory prayers should not perform supererogatory prayers, except for Witr and the Fajr (dawn) prayer of that specific day, and similar cases. Making up the Witr prayer is not obligatory; rather, it is recommended. It is permissible to make up more than one Witr prayer in a single day.