Golden, thanks. Yes, Plat Cat has a thermostat so it re-ignites automatically and runs the exhaust fan then. I plan on keeping low 70s inside when I'm awake and 64 when I'm sleeping.
I hope there won't be 15F days or nights, the coldest could be 32-35F and only in the last pre-dawn hour, as usual in desert.
Yes, I know that leaving window open could save my bacon if anything goes wrong in a non-vented heater, but I don't want even to come close to the point when I need to be saved :)... The experience of another neighbor who once saw "stars" in his eyes when running a non-vented cat heater (not Olympian), even though he lived to tell the story and doesn't appear to be impaired any more than before, - this was convincing enough for me.