I might by usfull,
After I get pass the point when update allowed my to lunch the game menu (around 3 Gigs) I was able get to instaliation customisation options. I'm not a multiplayer person at all and Halo MCC is story only for me. So by unchecking multiplayer compenents in all for games I was able to cut the size of the update foro 73 to around 53 Gigs. It's still a lot but for my conection 20 Gigs it's a huge difference
Edit: I did not noticed that update is instaling Halo ODST. It is installing in dispite it's not a free add on and I don't have it. It have a padlock on so it have tu be unlock by purchesing. Im not planing to buy it any time sone I uncheck it. I was uble to cut whole think to 45 Gigs