At no more than 5 acres & no deeper than 15ft ... I'd be casting jigs & Roadrunners, anywhere & everywhere Thumbs Up
Fall fish are going to be wherever the baitfish are, feeding up for the cold water period.
I wouldn't think it necessary to be night fishing, right now. Locally, the fish were/are being caught on flats & around deep submerged brushpiles, and in channels or along channel edges ... generally in 15-20ft of water, and just off the bottom. This was with surface water temps in the 80's. With the cooling off of the water temps, I expect the White Crappie to suspend over brush or channels & channel edges, and the Black Crappie to migrate into the creeks/bays & come a little shallower & closer to the bank. Both will be keying in on the comings & goings of the baitfish populations.
If your fish don't have any place else to go ... and there's no heavy concentration of baitfish in these backwater sloughs, then you might want to use a bait that mimics the fry or young of the year of any other species that's trapped in there with them. While Crappie prefer to eat soft spined fish (like chubs, shiners, shad species) ... they have no qualms about eating hard spined fish (like Sunfish, or their own species), if that's the only food, or most abundant food available.
... cp