Bassman, don't change the water temperature! Your octo seems quite happy with the temperature you have now.
The lower temperature discussion applies to bimacs, which are sometimes kept at much higher temperatures than the ocean water they come from, sometimes even over 75 degrees. They can tolerate this, but seem to live longer (and possibly be less active) at lower temperatures (one public aquarium keeps theirs at 59 degrees)
With the exception of bimacs, most of our octopuses come from warmer waters.
These sound like very interactive octopuses, fun to keep!
Nancy