Sorry, I can't comment directly on your variety. However
1) Plants in containers are more vulnerable to cold than in ground plants. The rule of thumb is to subtract 2 zones for unprotected plants in pots.
2) I have Duke, Chamberlin, and Blue Crop blueberries in zone 5 (Northern Ohio). I bury the pots in leaves and they have done well in the past. But I think that your SHB plants are probably less hardy.
3) I have a couple of other plants in pots that are less cold hardy. I drag them into the garage for the winter. If you store them in the garage, make sure the soil doesn't dry out during the winter. One guy suggests occasionally piling snow on the container to slowly water the plants as the snow melts.

Hopefully someone with more specific information will also comment.

Ed,I think I read on University of Florida's website that Sweetcrisp was good to about zone 6.So your garage may be the better place for them. Brady

Thanks for the responses. Last year I only had 2 northern varieties and I overwintered them in the garage, but it was too warm for them. This year I now have 5 northern varieties and they will definitely stay outside and should be fine. We have plenty of snow for insulation.

My 2 southern varieties will definitely go in the garage.

Ed, did your sweet crisp come from Florida Hill Nursery? Ive only got 1 left from them and Im almost 100% sure its not Sweet Crisp. I say that from compairing it to the real ones I got from Just Fruits and Exotics. Will this be the first spring you fruited it? Did you fruit Farthing last spring? If so did you like the berries?

blueboy- Did not get Sweetcrisp from FHN. Got it from Horner Farms. Yes this will be the first spring for fruit for either of them. They were 1 year old plants last spring, so I was planning to let them fruit a little next year. The Farthing was recommended to me for the production.....not sure how they will taste.

I just talk to owner Horner Farms Sweet Crisp needs Farthing as cross pollinator.

Really gator rider?I thought any Southern Highbush will work? Brady

My Sweetcrisp has set without Farthing. In fact as much as I can tell from last year with almost no bees, Sweetcrisp will set without pollination. YMMV

Farthing and sweet crisp this give full fruit set on each plant types both are partially self-incompatible.

When I said that Farthing was recommended to me for the production, what I should have said was that Farthing was recommended to me for 'their' production of berries. They are supposedly heavy producers, which hopefully I will find out in the next few years. As was already adequately explained above, Sweetcrisp doesn't need a Farthing to produce.

I talked to the nursery about winterizing my blueberry trees and they advised against it they said blueberry needs chell hours and if you take them inside they will not produce. I listed to them and got no fruit the freezing weather killed them to the ground then they grew weak and miserable. may be I should take them inside or cover the pots with something.

What varieties are yours foolishpleasure?
Chill hours usually happen between 32-45 degrees Fahrenheit.
Some Northern Highbush can take temperatures below -20F.While others,like Rabbiteyes and Southern Highbush need a somewhat warmer climate or protection against extreme cold.
Each Blueberry plant needs a certain amount of time to rest at the chill temperature and every variety is usually designated with a number of hours.
A garage is okay to bring them into during the winter as long as it's under 45 degrees F or yes,they can be covered.Even snow can work.I'd probably use some type of mulch around them also or bury the container in the ground. Brady

As Brady suggested, foolishpleasure, it really depends on the bush type. I'm also in zone 7B (NC Piedmont), and my potted northern high bush varieties stay outside year round with no obvious detrimental effects. In case of early bud break, I do provide overnight protection when there's a threat of a heavy frost or temps are forecast to dip below 30F or so. I bought a lot of new plants this spring, including some southern high bush and rabbiteye varieties, and I do plan to provide a bit more protection for them when it gets especially chilly (when temps are below the low 20s, which isn't that often in my area).

I have 6 blueberry plants and all in containers.
1 Duke 1 Bluecrop 2 Rabiteye 2 Honeyberry. I know that the rabbiteye is a southren bush and the rest are cold hardy. For example the honeyberry is a native of Siberia. But I am not taking any chances I will take them inside my unheated Garage where Temp is about 35 but never goes below zero.

foolishpleasure,
I have all those too.Yes,the Duke and Bluecrop should be hardy in zone 7 unless they are very young or are in tiny containers and the Honeyberries can go way down in cold.Rabbiteyes though may be more temperature sensitive. Brady