If I have a guest for one night, and they seem reasonably clean, I would not want them to strip the bed. I do not see the need to wash the sheets every time a clean body lies in them. So it would be a lot more work for me to have to re-make the bed.
I would probably ask if they planned to wash them or leave them on. But on the other hand, sometimes I get the impression that everybody thinks you SHOULD wash the sheets, so it could be embarrassing to admit that you’re not planning to. In which case, rather than ask, I’d just make the bed. It is much easier to strip the sheets later than get stuck doing laundry you didn’t plan for or remake the bed.
I definitely wouldn’t just leave the bed unmade though. If I did strip the sheets, I’d also fold the blankets, comfortors etc. and leave the bed looking as neat as possible.