bearisgray

After binding has been removed - if there was one -

You might consider looking at "quilt as you go" methods for adding on - which is what I would consider. I would try a couple of little sample/test runs on scrap just to get an idea of how to do it. (I have read about it, but not actually done it.)

Or if you really wanted to beat youself up - take the quilting out and then you have the three separate layers - and then you could add to the top - add to the backing - or get a larger one - and a larger batting - and then relayer, quilt, and bind.

If you have enough materials to just make another quilt, that's what I would do.

After trying to do remodeling of various things - usually it is so much easier to start over..

Sometimes a small quilt is "just the right size" for napping on top of the bed, or a couch quilt, or a lap quilt, or a child's quilt.

PS - depemding on your design/ pattern - it might be necessary to add to all four sides, instead of just two sides to make it look right.