I'm not sure it will work on the present generation of remote opening locks, but there used to be a light grease lubricant that you could inject into the key hole. It would spread to the inner workings and keep ice from forming and jamming the mechanism.

First place to stop is a local auto supply store and see what they have off the shelf. If nothing there, a call to the auto dealer service department might point you in the right direction.

Finally, I was never able to get the old trick of inserting a key into the lock, then heating the key with a lighter to work, but you never know. . .