Thank you for showing us your quilt.
Autumn colours are always a favourite of mine, and so I am quite drawn to it.
Of course, you can add borders to just the top and bottom, if that is what you want.
As they say ... Your Quilt! Your Rules!
The other way would be to extend your block design to make it longer.
Naturally, that would mean some reverse stitching, and perhaps you do not want to do that.
As for square vs. rectangular quilts ... you know how they will be used, as to which is better.
For me, squares are my go-to shape, not matter whether it is a bed or couch quilt.
That's what works best for me .......