The 5GB limit is just the free Mega limit. People seem to generally be fine with downloading double digit GBs for games like Wild Life or Subverse every time there's a new update. I can understand the argument someone else made about there being some major refactors to the code base. Still, if it was my game, I'd try to get the rest of the game in line with it and keep everything together, not bring back the "please insert disk 2" solution from 20 years ago.
Side note; did some testing, some minor compression could easily halve the image sizes without noticeable loss of quality.
