If you find it harder to open the car door in cold climates, this can be a sign of failing door seals. This happens when water gets inside the car seal and freezes there, causing the seal to swell up and solidify. When you experience door freezing, you should look for any tears in the door seal through which water can get in. Also, try cleaning and fixing the seal properly before looking for a replacement. But the seal can freeze in the extreme cold even if it is in good condition. To avoid this, you can try using some cooking spray as a lubricant on top of the seal.