343i would. :P

Also, astronomical overhauls of a game have happened before without requiring full-size file replacements. Such is the nature of modern patches.

A good example is High Voltage's PS3 port of Zone of the Enders. It ran at 720p, spent a lot of time below 30fps, and is just generally a very poor port, visually inaccurate, missing some effects, and running worse than the original PS2 release.

Konami hired Hexadrive to completely and totally overhaul the graphics and performance. The game is now rendering at 1280x1080, 50% higher. Post-process antialiasing was added. Screen elements like wires are rendered in a special line-drawing pass that makes them look almost perfectly antialiased. Some effects like depth of field have been restored and modernized. Elements that had previously been stretched in widescreen mode now display correctly. A large number of things which had previously mismatched the original PS2 release were corrected to make the visuals more appealing and faithful. And it runs at a mostly solid 60fps.

More here:
http://www.eurogamer.net/articles/digitalfoundry-how-konami-remade-zoe-hd-remaster

Zone of the Enders on PS3 is over 4GB. The patch? About 600MB.