It is permissible for one who is junub to sleep, but it is recommended for him to perform wudu’, and wash his private parts if he wants to eat, drink, sleep, or have intercourse
وَحَدَّثَنَا الْحَسَنُ بْنُ أَحْمَدَ بْنِ أَبِي شُعَيْبٍ الْحَرَّانِيُّ، حَدَّثَنَا مِسْكِينٌ، - يَعْنِي ابْنَ بُكَيْرٍ الْحَذَّاءَ - عَنْ شُعْبَةَ، عَنْ هِشَامِ بْنِ زَيْدٍ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يَطُوفُ عَلَى نِسَائِهِ بِغُسْلٍ وَاحِدٍ .
Anas reported: The Messenger of Allah (ﷺ) used to have sexual intercourse with his wives with a single bath.