and was pretty happy with the results..

So, I was lucky enough to get free tickets to the Packers/Lions game Sunday (!) The high temp Sunday was around 50, and it got down to the low 30's Sunday night. I decided Sunday morning before we left (around 10am) that I should turn off the furnace so I could see how much of a drop in temp we had with the furnace off all day.
When we got home, I was happy to see that the temp had actually gone up, to 72 (lots of windows on the south side, with a fairly high solar heat gain). It had gone up about 4 degrees.
Somehow, even though I looked at the thermostat to see that, it didn't occur to me to turn the furnace back on. I got up this morning & noticed that it seemed a little cool in the house. When I checked it, I realized that the furnace had been off since Sunday morning, & it was down to 67.
Granted, it's not THAT cold right now, but it seems that we're picking up enough heat during the day & holding on to it, that we don't really notice when the furnace is off.