There's a hole in floor, dear Liza, dear Liza. A great big one, dear Henry, dear Henry. There's a hole in the roof, too. Fortunately not nearly as big, but big enough that water is sneaking in somehow when it rains really hard. I discovered the latter after ripping down the drywall in that part of the kitchen. I created the former by ripping up rotted and termite-infested subflooring.
I ripped up a lot of subfloor today, and decided I'm going to rip up more that's spotty. So after making another dump run, I got another piece of T&G 3/4" for subflooring. The hole will be bigger than what's shown before I'm done. Including the old porch, it'll be three 4x8 sheets total, which ends up being two thirds of the kitchen. Hopefully that'll be enough.