From the programming side, what is the use case for
an image that size? I'm imagining a background that pans with a
sprite, which if it were me, I would personally slice the image
into large chunks and lazy-load them on an as-needed basis. This
would possibly lead to a better overall user experience as it
doesn't consume lots of memory at once (assuming you clean up a
cache) and generally doesn't cause noticeable pauses to load
large images. But such a solution may or may not be doable
depending on your use case.
Another hybrid option is slicing the image file and then
aggregating it after it's been decoded. If the JPEG decoder of
pygame.image.load() is to blame, loading individual tiles into
pygame.Surfaces and then creating one giant Surface and
blitting them all onto it may get around this constraint.
But I would personally do the lazy-load approach.