You have to enjoy it. There is so much work and responsibility to having dogs that you have to enjoy it. Mushing is a lifestyle and I believe everyone has to enjoy life - whatever they do. Canadian Eskimo and Greenland Eskimo dogs handle cold weather the best. As far as performing in race conditions, cold is a factor that you have to deal with.
Dogs can wear coats and belly protectors.
A dog with thick hair may require less attention in the cold but may not be able to handle the warm weather. Racing dogs need to be adaptable to conditions during the race. But for pure toughness in the cold, nothing beats Eskimo dogs. During the race your diet for the dogs is crucial. It is basically the same during training.