Nice setup. I added a solar air heater to my place. Just a temporary one . It will flawless begin heating my home from 9 until around 3 pm.
You can not ever go wrong adding insulation and making a outside wall thicker with it . I go into many homes now days in ms that has no insulation in them and they are heating with the 120 volt wal mart heater . They have no idea how much energy they are waisting.