You might look at some of the Marina websites, or guide websites, and see if they have a recent water temp reading. Or you might try calling the number listed for water generation schedules, and see if they have water temps (either in a recording, or ask the person answering the call) ... but, you'll have to realize "where" those temp readings were taken !! Toledo Bend is a BIG lake, and water temps could vary by 10deg or more, depending on location.
... cp