Winter brings with it a few special considerations when it comes to your transmission. During the first cold snap it’s common to have a transmission that won’t engage into Drive, but if you move the shifter to Manual Low it’ll engage just fine. After a few minutes of driving it’ll work fine for the rest of the day. This is most commonly the result of a failing component called a sprag; which is a one-way clutch. It’s not an immediate serious problem and other than the inconvenience it won’t cause other damage. The unfortunate part is in order to repair it you’ll need to have the transmission disassembled in order to get to it. Another consideration is getting stuck in the snow. Spinning the wheel in an effort to get out of a ditch can cause serious transmission damage. If you find yourself stuck in the snow try rocking the car by moving the shifter from drive to Reverse… gently. Otherwise call a tow truck; it’ll cost less than a new transmissions.