I asked Messenger of Allah ﷺ "Can any one of us sleep while he is Junub?" He replied, "Yes, if he performs ablution, he can sleep while he is Junub."  

أَنَّ عُمَرَ بْنَ الْخَطَّابِ سَأَلَ رَسُولَ اللَّهِ ﷺ أَيَرْقُدُ أَحَدُنَا وَهْوَ جُنُبٌ قَالَ نَعَمْ إِذَا تَوَضَّأَ أَحَدُكُمْ فَلْيَرْقُدْ وَهُوَ جُنُبٌ