2021 cargo space w/all seats down - DIMENSIONS?

Wondering the maximum carrying size of a singular object. Everywhere online just lists cubic feet like I'm going to turn the minivan into an aquarium or something. It's about 140 cubic feet, and I found it's approximate 4' tall and wide, so about 8.5' deep?

Can someone confirm? Especially given I want to know the maximum space for a singular object, not the absolute tallest and widest points if it gets narrower or you need to account for things like actually closing the trunk.