The way to answer your question is through research. I won't do it, but I'll tell you how I would do it if I wanted to.
Here and here are a list of all subtropical and temperate conifer forests. I didn't link boreal forest/taiga since thats not what you are asking about. The WWF descriptions of each biome usally will give you an altitude range for that biome. Here is map of all the world's biomes. From it you can figure out the latitude range for all the world's biomes.
If were into researching this, I would look up all the coniferous forests and put their minimum altitude and minimum latitude in a spreadsheet, then make a plot. You should get a trend line that maps the altitude and latitude for which coniferous forests make sense.
Also keep in mind, that though presence of conifers is positively correlated with drop in temperature, the same is probably not true about moisture. The mountain conifer forests of SW China get tons of monsoon rain, the temperate rainforests of Pacific Northwest and Chile are confierous, much of Japan is very wet and conferous, North Florida/South Georgia is all pine trees and plenty wet, etc. So conifers are not specifically adapted for cold and dry....just cold.
Also, as the example from North Florida shows, pine trees can be mysterious. This is a pine dominated landscape, but a couple hundred miles west in Louisiana there is the same (exact) climate, with broadleaf forests of live oak, tupelo, and hickory. What gives? In that case, its probably soil: pines do better on sandy Ultisols of the Gulf Coast Plain, while the broadleaves trees outcompete them on the alluvial Inceptisols of the Mississippi Delta.