I used to turn my thermostat down to 65 at nights. Then there was the house I had when I lived in St. Paul. The attic space was finished, except that it didn't have its own heat source ... and that was my bedroom ... I wouldn't do that now.
No, I'm not facing the lake ... I actually do have the AC on in summers because, yeah, the noise and the lights and the dirt/dust ... but ... I prefer it without AC.