I just heard an episode of the show that had a caller question the phrase, "It's so COLD to all get out." Which was determined to mean it is very cold. My take on this is that it is so cold everyone should get out of the cold. The same would be true for "it's so loud..." or "it's so hot..." Meaning everyone should get out of the noisy area or everyone find a cool place, respectively.
Your explanation might work for the examples you provide, but I've often heard the same expression in sentences like "He's as smart as all get-out", or "Those kittens are as cute as all get-out".
Another possibility is that the speaker ran two thoughts together and meant, "It's so cold! It's too cold to all get out".
I'm not sure why, but I've always assumed that "get-out" was just a euphemism for "hell".
It made some sense to me and makes the grammar work, so it's probably not the real etymology.
I'm with you, Lee. I consider it a euphemism for hell in this case.
In my imagination (no research done on this) the "get out" was anticipating an interruption from the listener to avoid the foul word the speaker would otherwise use. Perhaps your mother, upon hearing you use the word hell, would say "Get out!" "Get out of here if you're going to use that kind of language." (I have actually heard an aunt or two use that response to a cousin's word choice.)
In that sense, using "get-out" as a replacement would be like the practice of substituting the word bleep for some questionable language when speaking. "Get the bleep out of here." (Actually using the word bleep.) This would suggest the censorship methods used in broadcast television with seven-second delay.
It is perhaps a form of self-editing or self-censorship that has taken on a life of its own. That would be my initial theory.