Playing area (cushion nose to cushion nose) on a bar box is 39"x78" (slightly larger than a standard 7ft home table), on an 8ft standard it is 44"x88". For a bar box... A 15' room = 180" - 78", leaves 102" divided by 2 = 51" FROM THE NOSE OF THE CUSHION on each end of the table. With a standard 58" cue, you couldn't even pull the stick straight back to have the tip end at the cushion nose.
If you have the table angled in the room, you could improve part of that. I suggest you cut some sheet plastic to the dimensions of a bar box (play area and/or table case), then lay it out in the room & take some measuements to find out what you'd be up against in clearance from the corners to the wall.