I have quilted queen and king on my DSM. I just have an extra table behind my machine and a table on my left to hold the bulk. (Your ironing board is great for this) I just "smoosh" the parts I am not FMQing up under the arm. The key (for me) is to baste the quilt. I baste with water soluble thread, in a grid all over the quilt, then remove the basting pins. You could also stitch in the ditch around your blocks and accomplish the same. It just makes a huge difference to stabilize your quilt before starting. It is most definately possible and doable!