What is the ruling on one who prayed 'Isha on the road fearing its time would expire, then repeated the prayer upon reaching Muzdalifah?

Delaying the Maghrib prayer to combine it with Isha in Muzdalifah is a Sunnah (definition). The time for the Isha prayer extends until midnight. If there is a fear of the time expiring before reaching Muzdalifah, the prayer time should be brought forward. The scholars have unanimously agreed on the Sunnah of combining the prayers, in emulation of the Prophet's action (peace be upon him). Whoever prays Maghrib before reaching Muzdalifah without combining it has contravened the Sunnah, but their prayer is valid according to the majority of scholars. However, Abu Hanifah and Al-Thawri hold the view that it is not sufficient.