A Beech B200 King Air aircraft operated by Keewatin Air under flight KEW204, was conducting a medevac flight from Winnipeg, MB (CYWG) to Sanikiluaq, NU (CYSK) with 2 passengers and 2 crew members on board. While conducting a missed approach on runway 29, the aircraft deviated from the intended path and went off the side of the runway. One of the passengers sustained minor injuries. The aircraft sustained substantial damage. Findings as to causes and contributing factors 1. In the absence of precise data on the aircraft?s performance limitations, based on previous successful landings in similar wind conditions, and with an established plan to conduct a go-around if they had difficulty controlling the aircraft, the flight crew decided to conduct the approach with a crosswind component of 31 knots. 2. As the aircraft crossed the runway threshold, the first officer, who was monitoring the approach, did not notice any deviations or other signs that would lead him to make a go-around call. With the pilot-in-command able to maintain a stable approach, the flight crew was certain that a go-around could be conducted at any time if control difficulties arose once on the ground, and decided to land. 3. The combination of the strength of the crosswind and the degree of tire traction on the runway surface caused the aircraft to drift to the left. When the pilot-in-command realized that he was unable to control the drift after about 3 seconds, he conducted a go-around as planned, but the aircraft exited the runway surface immediately thereafter.