well in that case its not worth turning it down, you should leave it at 65. If you normally have it on 85 and you turn it down to 60 then thats a lot to make up for and your air will run until it makes up for it then it will cycle on and off as needed. In SoCal at 65 it probly doesnt run much if at all!!!
Anyway thats how I used to run mine when I had a house and it worked fine my bill usually ran within 2 or 3 dollars from month to month. Never from one extreme to the next......
i have just done a bit of research on this and according to the majority of resources found, came up with the following.
It does depend a lot on the structure of the house obviously but in general it is better to turn your heat down when you are not going to be there for >3 hours. you should never turn it down more then 55 degree though. According to the gas company I called, it is less efficient for the house to reheat itself if the difference is greater then 15 degrees. they also said that on average you save 3% monthly on your heating bill for each degree cooler you keep your home. So if you normally keep it at 70, then start keeping it at 65, you can expect to save up to 15% on your next gas bill.
Has anyone seen any real difference with the plastic wrap over the windows? I have a huge glass slider in the place I'm moving into and imagine it will contribute to a lot of energy loss.