That really depends on the humidity. I can take a desert 90F or even 100F all day without AC without issue but 80F temps with a 70F dew point absolutely kills me. I lived in my area without AC for years. I never got used to it, I just stopped functioning when it got hot and muggy.

Mine is programmable. In winter it’s set to 65F at night and 68F durring the day. When unoccupied it also goes to 65F. I’d love to be able to set it lower because I love the cold but my pet snake probably wouldn’t appreciate it even with their hot rock and heat lamp. Durring the summer I have it set to 68F while sleeping 72F durring the day and 78F while unoccupied. I don’t shut the AC off while unoccupied because in my area humidity is a much bigger issue in the summer than temperature and removing latent heat takes a long time if you let it build up all day. Currently working on refitting my system for better on demand latent heat removal.