My car's keyhole is frozen!?

no problem/ heat the key up with a lighter or similar . you may have to hold it with pliers if it is all metal. put the key back into lock and keep wiggling it. if it doesn't do it first time , re-heat the key and try again. once it is working again you need to squirt 'wd40' into the lock and all over the key. replace the key and give it a good working over until you are satisfied that the lock is working freely again. hopefully you won't get any more trouble with it this year.