I too am space challenged when it comes to basting large quilts. After watching a video online, I purchased some very straight 1X3 pine boards and used Sharon Schambers method of rolling the fabric on the boards on my dining room table. I have done one quilt with her herringbone stitch basting and one using pins for basting and the boards worked great both ways. Sure is easier on the back and the old knees!
http://sharonschambernetwork.com/fre...ing/index.html
Maybe this would be a solution for you also.