A hydrokinetic turbine extracts energy from river currents and can enable communities worldwide to establish micro-grids to address part of their base loads. Hydrokinetic turbines offer a viable solution to produce power year-round to displace diesel generation in northern communities. However, these turbines must operate in reduced winter flows and not be impacted by ice. A passive-counter-torque and river-prototype hydrokinetic turbine integrated system is presented that offers a simpler and lower-cost approach to deploy, operate and maintain hydrokinetic turbines year-round in cold climates. A 500-W river prototype designed with a 0.48 m diameter two-blade impeller is optimized, built and tested. It produces a torque of 24.44 Nm at 200 RPM for a flow velocity of 2.0 m/s. For this in-situ prototype, shrouds, winglets, and wingtips are developed and optimized to reduce the levelized cost of electricity and micro-grid performance when flow velocities are lower than the design set point of 2.0 m/s. Such off-design conditions are mainly experienced during winter seasons. Numerical simulations confirm that the winglet design maintains the design power when experiencing up to 18% reduction in velocity. Various design combinations were tested by varying component dimensions: 2,216 combinations for shrouds and 4,103 for winglets. The optimal results were achieved using the shrouds, while the winglets were found to have the advantage to prevent stalling. Testing of the prototype turbine at the Canadian Hydrokinetic Turbine Testing Centre shows that the counter-torque design selected was stable. However, using a field vacuum pump to control the ballast in the configuration tested needs to be reconsidered.