Does Tecate need the same cold-climate heat pump as higher-elevation backcountry towns?
Not usually, no. At 1,700 feet with milder winters than Julian, Pine Valley, or Mount Laguna, Tecate homes generally do fine with a standard heat pump rather than a cold-climate-rated model, which keeps equipment cost a bit lower. The bigger factor here is summer heat, so sizing for the 95 to 105 degree afternoons matters more than winter heating capacity.