I plan on looking fabulous when he shows up, whether I have plans or not.
Definitely! Other things you could do: Have a vase of fresh flowers on display. If he asks who sent them, just tell him "a friend". If he asks which one, just tell him "you don't know them". Then change the subject.
Have a couple of used wine glasses on the coffee table (I was gonna say patio table them remember you said it was cold where you are!). If he asks who was over, just say "a friend - you don't know them". Like I said, don't date now if you have hopes of him coming back, but nothing wrong with trying to jolt him back to reality by giving him the IMPRESSION that you might be dating.