Best way to practice for btft if no space at home or gym nearby.

Starting bmq on the 12th of January, and im getting abit nervous about the btft, specifically the 20 meter rushes, the other events i dont believe ill have any issues with im naturally a pretty fast walker, and the sandbag drag seems to have a pretty lenient time frame. Any tips on how to train for that specific event when I dont really have room at home, or a gym nearby with adequate space. It's also the middle of winter, so in theory I could do it outside in a public parking lot but im abit worried about the slipping hazard and the need to be more dressed up then I would be in the actual testing environment.