I would list it now. Home showings are hard when your trying to pack. If it's gone now it easier to pack up and go later.
Also I'd make a condition that their possesion is closing date on your home. Pull a few grand out of the purchase price as "rent" for the new owners. Very easy actually
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents... some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new Dark Age."
-H.P. Lovecraft