A year or so ago, I started reading a Cormac McCarthy book (The Crossing, I think) to my 4-5 yo. We got 100 pages in before life got in the way. I'd modify sequences on the fly if they were inappropriate, but the main thing was stopping after each sentence or two to define words or act out the action. e.g., if a horse had been hobbled, or the wolf was being tied up in a certain way, we'd get ribbon and pretend to tie something up. Sounds tediously slow but it wasn't too bad.

He was enthralled but I think at some point the story becomes more grim. Plus, it'd be hard to resume now because he's old enough to read over my shoulder and there'd be no way of hiding violent bits then.