During winter, certain fish species remain active while others become dormant, which is characterized by low metabolic rate, fasting, and negligible or negative growth. We hypothesized that winter dormancy is a survival strategy that arises in poleward species that tolerate severe, uncompensated constraints of cold on physiological performance. To date, we have measured the metabolic, exercise, and digestive performance of cunner (Tautogolabrus adspersus), a model winter-dormant fish, acclimated or acutely exposed to a wide range of temperatures (2-26°C). Contrary to our hypothesis, we found partial cold compensation of nearly all metabolic and exercise performance metrics studied, similar to winter-active species. Further, after bypassing the behavioural fasting response during dormancy using repeated force-feeding during cold acclimation, cunner were able to digest food and subsequently exhibit positive growth compared to negative growth of the voluntarily fasting fish. Only responsiveness to stimuli during the C-start escape response was greatly constrained in the cold even after acclimation, suggesting a thermal sensory limitation that may help explain the need to become dormant. To further explore this idea, we measured the C-start escape performance of six phylogenetically-diverse species along the spectrum of overwintering strategies from winter-dormant to winter-lethargic to winter-active. As we predicted, responsiveness was greater and more plastic in the winter-lethargic and -active species compared to -dormant species. While most physiological performance traits in cold dormant fish remain robust, impaired responsiveness to C-start stimuli may be a weak thermal link driving dormancy as an overwintering strategy among fishes.