Demand Response (DR) has the potential to reduce constraints imposed on the electricity grid hence delaying investments in the production and distribution infrastructures needed to supply customers at times of high demand. Field studies of DR strategies in commercial and institutional (CI) buildings has been the focus of many studies, most of them addressing cooling load. For some winter peaking utilities, CI customers contribute to a significant portion of the grid's winter peak, especially if those buildings use electricity as their main heating energy source. A field study involving five all-electric facilities was conducted to assess potential peak load reductions of winter DR strategies. Customized HVAC-only DR strategies were identified, implemented into the building automation systems (BAS) and activated manually during winter test events. The results of this field study show that DR strategies can lead to a significant peak load reduction during winter peak periods (31 to 59%) with a slight increase in daily energy consumption. A comfort analysis was conducted based on submetering, surveys and BAS data; most sites showed slight to moderate discomfort while some saw an increase in comfort on the coldest days. Guidelines were established for the implementation of winter DR strategies.