Really good point to scale back so that the quilt makes sense on the bed.
I just measured the top+sides of the deep double bed that I have now and 80 inches would work well on it. So, I'll make an 80 inch square quilt with no border (to stay true to the barn-quilt look when it is hanging in the barn).
Thanks for the congratulations and for all of the great input! Really helpful, especially for a newbie like me who loves quilting and fabrics, but does not know what will be most effective (like staying under the 24.5 inch length of my ruler!).