Apparently none of these responders drive POS cars in freezing areas. (Not that a Camry is POS
However, here in Iowa we do get some freezing BS precipitation that can really be a bitch.
Most of the suggestions are good.
I have had to use Heat (the stuff you put in your gas) to un-freeze locks before. Just poke a really small hole in the foil without removing it, and it's like a squirt gun, just squeeze. Maybe squirt a little with the key half way in, etc.
As far as the doors freezing shut the best defense is a good offense as noted, silicone on the seals and clean door latches are really important. Cleaning door latches is not fun, and there are no easy ways, but in most cases there is no other option. The original grease will have dried out long ago, and they do see some dust, dirt, and wear particles.