I used a Salamander bag to get my Grande all around the world, it does not close all the way, but it does good enough. The quality seemed bad at first but it lasted several cross-ocean transits and no zipper busts.
That being said it is the only real commercially available bag. One of my bros put grommets in a shipping bag that kayaks come in- like the ones jackson sends their boats in- and sewed on some handles, and it has no zipper issues, so if you are crafty that might work.
hope it helps