If you really want it to be a bed quilt, perhaps take off a row or two of the fence rail blocks and incorporate them into one of multiple borders along with some coordinating fabrics as others have suggested - it might make the whole more cohesive. I know it involves a stitch ripper but it's one possibility. :-)

I might go with the ides to rearrange the blocks a bit for a size difference.

To make it larger I would match one of the colors you want to emphasize with a narrow solid border (the width of one rail) and then chose a multi-color large scale print. You aren't going to be able to match exactly, but look to coordinate and change scale with something that has a bit of complexity/flecks.

Maybe go a bit wild like these Australian prints:
https://www.equilter.com/category/19...-+-new-zealand

Thanks for the ideas everyone. Feel free to keep leaving suggestions :)

I should mention when I say "match the fabrics" Im meaning more complimentary, not find the exact same fabrics. Like trying to find the same shade of blue but with a different print on it.

look up some quilts like that and see what others did. borders sound like the fix to me. good luck!