Let’s be blunt. Rosemary dies for real at around 10°F (-12°C). At that point, it’s not “dormant.” It’s dead.
Same goes for prolonged heat above 115°F. It just cooks. Like a steak, but with fewer side dishes.
So here’s the cheat sheet: 20°F to 100°F is the sweet spot. Anything outside that, and you need to intervene. Move it, cover it, or kiss it goodbye.