Ruthie, I've had this challenge before and it was a puzzle for me, too. Every source I had advised that the quilt sandwich be one big flat piece before the basting could be done. I didn't have that much space! I borrowed a long folding banquet-size table from a neighbor and basted in sections from the center of the quilt out. It required a lot of taping...and pulling the taping...and taping again and again to be sure everything stayed flat...but it was a comfortable height for me and it worked. I'm imagining you basting a quilt outside in the yard and have to admire how resourceful you are !! Wow!