My bill was quite a bit less when I was working too...I turned it down to 62 as well and I'd get home before the kids so I would zip it back up to about 65 to start warming it up and then go from there up to 68. A huge part of our bill is the insulation. Our windows are as old as this house and need to be replaced. I know we get some cold air that comes in from there.
My apartment complex put in new windows and doors last summer. It makes a HUGE difference.
I turn my heat off when I leave for work, except for those unfortunate times when I left it on all day long.
I really need a programmable thermostat here, but I don't know if I can get away with installing one. I suppose I could take it with me when I move out.