You were right about chapter 5, 6 and the Epilogues taking forever. Just left the ranch from Epilogue one and still have a ways to go. There was some serious fluff in there. The pacing, especially the Indian story sections were so slow. Also they just would not shut up with the same bickering between Arthur and Dutch. I knew how the story was to end going in. The funny thing is that once I did contract tuberculosis, I stopped wanting to do any of the side stuff. It was kind of genius on Rockstars end. They made it near impossible to gain weight, so hunting for food felt like a waste. Find new animals? Nah, going to die soon. Upgrade stuff by hunting? No, but to be fair you are really overpowered by end game as it is. Always coughing and pale as a ghost. I got my achievement for creating a completely evil Arthur, only to end up right in the middle because I sided with the story into doing going things with my money. Had, plenty and can't take it with me.
Now if we were back in the days when RS made DLC for single-player stuff. I would love to have another Undead Nightmare where you play as Sadie Adler (my favorite character in the game). Charles would be number two. Javier was my second favorite until he sided with Dutch. For me that was the biggest betrayal.