If feasible, and if it won't bother you to look at, consider placing it slightly cockeyed in the space. Doing this I was able to prevent a short-cue situation all the way down one wall, but rather just very small spaces in two corners (3 foot cue), and a third corner (4 foot cue). A little strange to look at, but it did make for more normally-playable table area. In my case, I did have a fairly wide opening on one wall.
That makes sense.. but I'm pretty OCD and don't think my mind can handle that lol ... it being crooked would drive me crazy haha