It sounds like you fish a little bigger water than I typically do, but I'll take a shot. I think the crankbait and spinnerbait ideas both make sense. This might be a place to try a twin-spin, which in my experience tend to get and stay deep. I also started experimenting with small lipless cranks last year in similar situations with pretty good results. They fall fast and can be worked in a variety of ways at a variety of depths. Perhaps the most universal bait I fish is a ballhead or mushroom head jig head with trailer of your choice. You can key the weight to the depth you are looking to fish and then swap out trailers depending on your approach. A curl tailed grub can be fished at almost any speed or depth. You could drag bottom with a creature bait or craw-imitator. A little finesse worm can also work wonders. Variety and simplicity. I don't believe that fish must be finessed outside of 55-70 degrees. If I had to go low and slow, ned rigs and tubes would be at the top of my list as would a finesse jig with a craw trailer.
I'd love to hear what you end up trying and how it works for you.
