Asia—one of the world’s most densely populated regions—faces pressures from water scarcity, industrial pollution, and the environmental demands of infrastructure construction. Reclaimed asphalt pavement (RAP) technology, combined with warm-mix (WM) technology, is a key pathway toward achieving low-carbon road engineering and reducing resource consumption. However, research on the environmental adaptability of these technologies under Asian climatic conditions (e.g., frequent freeze–thaw cycles and prevalent salt-corrosion environments) remains insufficient. This study focuses on WM recycled asphalt mixtures (WMRAM) and innovatively introduces WM recycled asphalt mortar (WMRAMO) as the core medium. Using fatigue tests on WM recycled asphalt (WMRA), WMRAMO, and WMRAM and damage-mechanics indices, we systematically analyzed the effects of typical Asian environmental factors (freeze–thaw cycles, salt solution concentration) on fatigue performance. Results showed that under optimal WM recycling processes, WMRAM’s fatigue performance outperformed traditional hot-mix asphalt mixtures, providing technical support for low-carbon road construction in Asia. Freeze–thaw cycles and salt solution concentration had markedly opposite effects on microcrack propagation and fatigue failure. Meanwhile, a high RAP content exacerbated initial microdamage, leading to unstable fatigue performance—this finding explains the core cause of discrepancies in existing research. A correlation between WMRAMO and WMRAM fatigue life, based on RAP content and loading strain, was established, enabling the prediction of WMRAM fatigue life through mortar-scale tests, offering a new method for material design in road engineering in cold regions of Asia. This research fills a gap in environmental synergy studies of WMRA technology under climatic conditions common in cold regions of Asia, providing a scientific basis for balancing infrastructure development and environmental protection.