My largest was California King - several of them. Why not do a straight-line quilting with a walking foot? You can do it in sections, you know, and join them later. Go for it!

87" x 87". Do a small section at a time. Roll both sides first. I start quilting in the middle. A great tip I got from this website is to put your sewing Mach table against the wall if you can so the quilt is not constantly sliding off the work surface and use dining room chairs up against the table (backwards) if you cannot do that. I have to use the chairs on 2 sides of my table. Take your time. I was very happy to finish quilting the quilt! I free motion quilt and it looks nice.