What are the chances another coach seat will open up on my Dec. Flight

[chirurgeon]

I booked my air transportation a couple months ago for my Dec 2-11 trip. Non stop USAir, only $219. Now I am thinking of adding a person to my trip and the coach fare is listed as sold out. Does anyone see a possiblity of a coach seat opening up on my flight to Orlando? The flight home still has seats available.

TIA

 

[DebbieB]

A seat may open up but it's going to be very expensive, probably full fare.