I'm under the impression that once started, your car doesn't know the difference if it's going 10 miles or cross country. When the engine temp is in the normal range, any moisture in the crankcase will evaporate. If the oil is in good condition, it should do what it was intended to do. In colder temps, moisture will remain in the crankcase longer as it won't get the heat needed to evaporate, like in the summer months. I've "short tripped" motors in different brand vehicles over the years and never had an issue. I've always said the motor in your car is the most durable part of the car. You will have issues with every other part of your car, but the motor will allow you to drive it to the junk yard when everything else gives up.,,