If you camp down in the bottom of a canyon, no matter the elevation, it will be much colder than if you camped up out of the bottom. I've walked out of frosty creek bottoms and felt the temps rising as I ascended - the reverse is also true. Cold sinks.

Conversely, camping at the tops of ridges or peaks will also be cold, due to wind chill.

One of the many reasons I favor the hammock - can pitch on a slope if there are no flat areas/benches. Of course, if it's too steep, getting out to pee can be a real adventure!

Topography makes a huge difference. And mountains can change their weather - I've had the temps plummet to 30 degrees below what was predicted by NOAA. My recommendation is to bring enough that you will be comfortable 10 degrees below the forecasted lows, and you will probably survive something lower than that well enough.