Knobs require more effort to clean... eh... nevermind.

My Galaxy S5 Active, in Ultra Power Save mode would last 12 days according to it's in phone estimate. I was never able to push it in that mode the whole way through, but 2 days sipped about 10 percent of my battery when I tried, so I fully believe it was possible on that device. It downclocked the processor, turned basically everything off, like you said, and even lowered the display resolution and color to greyscale. I don't think I've seen a later phone than that with such a huge Ultra Power Saver.

Let the bodies hit the floor, as you throw stuff into the trash.

Nothing happened! Our health was on vacation!

You know that floor safe where you keep 10 grand? There's 5 grand in there. Don't, make, me, wait.