Like Charlie mentioned, you should be able to protect your veggies for a while by covering them. Earlier, I stapled heavy opaque plastic sheeting on stakes surrounding a small area, and the tomatoes and the bush beans inside were very happy. When it got colder, I clothes-pinned a light-weight fleece cover over them and that got them through a couple of freezing temps... until it plummeted down to 26Ã‚ÂºF.
I still have carrots, turnips, daikon, and kale -- and what I'm pretty sure is claytona
-- in there though. We had a windstorm and the light-weight got all ripped up, so I've replaced with a heavy-weight (tied down with rope and pegs). Now that all the flowering veggies are gone, they probably won't need as much light anyway. For okra and tomatoes, I imagine CLEAR plastic sheeting would work better.
Oh! Just remembered -- if you can get hold of a roll of bubblewrap, they're supposed to be great for this... hmmm I might try this myself.