I just move the pots to where they are out of the wind & put extra wind barrier around the pots, or bury the pots for winter.

IME, a potted plant should be rated one zone colder unless you are burying them.

I stack a bunch in a flower bed behind my garage. This protects them from the east wind. Then I put bales of straw around the outside of the pile and then fill it with leaves or put bags of leaves over the top. I have also buried the pots but this is more work. I have never lost one over the winter.

I just posted the above image on my blog, showing the 10 pots that were wintered over this winter in my zone 6/7 garden. They were in a sunny, moderately sheltered spot with good drainage and they simply had mulch around them. I started pulling the mulch back this week.You can't tell it in the picture because some were barely peeking out but all of them survived the winter! The link is listed below.

Here is a link that might be useful: The Bones of the garden

I dont do anything to mine and they have all survived just fine.

jean