Finally got some info back regarding my BIL and his wife, who are located in the Englewood area (south of Sarasota by about 45 minutes, and no more than a couple miles from the Gulf).
Ian's eye passed right over them, so they got hammered hard.
They are OK, but their house was damaged somewhat. No details other than part of their fence is missing, and several trees uprooted. If I were to guess, also based on some local information (but not from him), their lanai -- an attached structure to their house enclosing their pool -- may have either blown away or floated away. As I recall, it wasn't a very solid structure. Lots of screens and lightweight aluminum.
Mrs E and I may go down there to help clean up. They were prepared with the more-expensive impact-resistant doors and windows, but from the sound of things, there's a lot of work to do.