Except for sustained REALLY hot or cold, I try to keep my house within 10F degrees of the outside and just wear heavier or lighter clothin, etc. The change from toasty warm to freezing when you go out or just open a door in winter just makes the difference more noticed, and is a great way to get a chill IMHO. Ceiling fans and air circulation with good insulation should keep a house comfortable most of the time. And yes - I know some of us have far greater extremes to deal with and therefore have to have different heating/cooling provisions.
It hit 115F here late last week and I did not even think to turn on the split system a/c. The house remained a comfortable 77F even at the hottest part of the day. Why would I want to drop the temp to 70F? The difference between the inside and outside made the interior feel cool. In winter it can be 45F outside, but if the interior temp is
55F during the day and maybe just a bit warmer when I am sitting at night (with a quilt over my knees of course! lol) that is pretty comfortable for me. When I go to bed at night in winter I drop the heating to the lowest setting (about 48F I think?) and I don't turn it up the next day until I feel cold - which sometimes isn't until the next night.
I have never understood why anyone would want to live in house with a constant temperature year round. Not criticizing - just commenting. Energy concerns will probably force all of us (or at least our children) to adjust our expectations in the not-too-distant-future anyway.