I thought that the "change your needle every 8 hours" rule applied to 8 hours of embroidery, which is a LOT more stitches. In 8 hours of embroidery a person could do 100,000 stitches. I doubt if a kingsize quilt has 100,000 stitches in it. Maybe an appliqued quilt if all the appliques are outlined in a machine satin stitch.
Once I find an internet site to buy needles 50 at a time at a much reduced price, now I can't find it again. Does anyone have a good source for reduced price titanium needles?