In cold climates, cyclic freeze-thaw (F-T) action poses significant challenges to the mechanical stability of geocell-reinforced earth structures. Limited studies have evaluated the F-T responses of the geocell-reinforced earth structures; however, no research has reported the performance of geocell itself under F-T cycles. To fill this research gap, this study investigated the strain of novel polymeric alloy (NPA) geocells immersed in water under F-T cycles with high-resolution distributed fiber optic sensors (DFOS). Leveraging the unique capability of DFOS to provide continuous, distributed measurements of physical parameters along the optical fiber’s path, it captured localized strain heterogeneity and material degradation patterns across the geocell structure. This technology provides unparalleled benefits as compared to conventional point-based and electrical measurement methods, such as strain gauges. Experimental results revealed compressive strain accumulation during the freezing phase, partial strain recovery in the thawing phase, and cumulative residual deformation across successive F-T cycles. Variations in results across measurement points highlighted spatial heterogeneity in geocell response. The findings from this ongoing study provided some insights into the material durability, while the longer-term monitoring would advance the understanding of geocell material degradation by F-T cycles, informing more resilient design and improved long-term performance predictions for geocell-reinforced earth structures.