Our Homestead

if you have central a/c.  You can close off registers if you have them.  I still think that cooling down the house for an hour or two, obviously shutting the windows, that you will go to sleep and the bedroom will still be cold.

My summer bill is always much higher than my winter bill because of the air conditioner.
I look doe ways to compensate for that like using the oven less but the bill is still higher.
It's easy to use the oven less often in summer because we eat more salads and stuff.

I am freezing with the central air conditioning.  I rarely have it on in the summer.  I prefer warm over cold.  I hate humid, but it would have to be extremely humid for me to even turn it on!  I save a bundle of money in the summertime by not using it!  Also, it dries out the air, which is actually the first thing it does.  I need some humidity in my bedroom.  Can you just turn it on to cool down your home and then shut it off?

Maybe it depends on where you live and how hot it gets but honestly I can't think of too many places where it gets too hot at night.
A fan works really well for me. I hate being cold and I almost never use the air conditioner. 
I only use it while I'm cooking. The only AC I have is located in my kitchen.

I've never seen the need to let me A.C. run overnight.
I sleep in a light T-shirt under just a sheet.  I have this water bottle that I fill with hot water in wintertime to keep my feet warm.
In summer when it's hot, I till it with ice cold water and put it in the fridge. Keeps me nice and cool in bed when need be.

Unfortunately I live upstairs so it can get pretty hot up here but I'll turn a fan on before I turn the A.C. on.
Something else that helps save on AC is making salads instead of cooking big meals. You use the stove less and thus will need the A.C. less.