Susan, if you have plants that need to be protected from frost, but you can't bring them into the house, you can always throw a sheet over them. That's what most people do here. Since it normally only drops to freezing for a few hours during the night, we just toss an old sheet over the plants to keep the frost off and they're fine. I know someone who's kept a pulmeria tree alive that way for over 5 years. The bad thing about that is that you have to watch the weather carefully & make sure you get your plants covered EVERY time it freezes. That's a bit too much work for me. I do have some plants that should be covered (like aloe), but I usually just leave it. The aloe will get a little brown and funky, but it'll grow back fine in the spring. If you want to be a little more high tech, I did see some really neat plant cover "umbrellas" on some web site. I don't remember where I saw them....maybe Stokes? It was like a vinyl umbrella tent that you put over your plants & it acts like a cold frame. That way they still get the light and warmth during the day if you forget to take the cover off. Also, it depends on what you grow. Many tropicals that are listed as hardy to zone 10, are actually root hardy further north. A frost will kill it back to the ground, but it'll come back in spring. My cupheas do that. Some places list them as hardy to zone 10, but they're actually root hardy to about 20 degrees F.
--Sharry