My garden is at its prime

The combination of neglect and a wet hot summer has made my garden bountiful. I picked a case of ripe and near ripe tomatoes last night and a few ears of corn. The cabbage, onions and peppers are still going strong and now the broccoli has gone to flower (missed picking it on time). But I still have plenty of green tomatoes and ears of corn, and cucumbers that are still developing. Now that the weather is turning cold-what is the easiest way to keep them going and to shield them from the cold? Can they still grow in the colder climates? Is just covering them at night with a plastic sheath enough to ward off the Chicago elements?

id like to know the same. i have a few plants that need to ripen