Is it permissible to pray Witr in congregation with one's wife daily before sleep, and to vocalize the recitation therein?

The fundamental principle for the Witr prayer and other supererogatory prayers is that they should be performed individually. However, it is permissible to pray them in congregation occasionally, as the Prophet, peace and blessings be upon him, did so. He prayed Witr in congregation with Anas, his mother, and the orphan, and also with Ibn Abbas.

As for consistently performing the Witr prayer in congregation, this is not advisable. Some scholars have even considered it a disliked innovation. It is recommended to recite aloud in the Witr prayer, whether performed in congregation or individually, as long as it does not disturb another worshipper.