We have only had one school night sleepover.
DS's friend's mother was going in for breast cancer surgery and didn't want her son to miss school. So she asked if he could stay the night.
Of course he could!
Normally the child would sleep in a sleeping bag an on an air bed in DS's room during a sleepover.
However, since it was a school night, the child slept in the guest room.
It turned out just fine.
Normally a school night sleepover is a "no way", however, circumstances may dictate a change in opinion.