They are in very small pots and appear to be root bound. I live in zone 7 B Spartanburg Greenville area of SC. I have never grown hardy fushias and I need advice about how to pot them, winter them over and care for them.

OTOH kinda troublesome to overwinter potted plants, especially Fuchsias that do not deal well with dry heat (say, indoors).

Your decision. To overwinter outdoors, just dig a big hole for them ('cause you don't want the rootball to hit the interface between where you dug and where you didn't), unpot the rootball, then bury them somewhat deeper than they were potted.

Once they are established they will be fully roothardy BUT NOT tophardy. (Don't worry; not a problem because they bloom on new wood). They will freeze to the ground in hard winters (maybe even average winters in z7). However, because they are NOT established, MAKE SURE THE ROOTBALL DOESN'T FREEZE. You need to judge where your frostline is, and cover them with enough dirt or mulch to keep them from freezing.

They would probably actually survive. Fuchsias have such incredible regenerative ability I have seen them recover from badly freeze-split wood.

Rootbound is not too much of a problem as they have fine but aggressive roots.

Fuchsias are heavy feeders which is not surprising as they are also heavy bloomers. You might want to mix an organic fertilizer with them when you plant them out. You will want to feed them regularly next growing season.

A word about siting: in your climate, avoid afternoon sun. They are naturally fairly shade-tolerant anyway. Grow them in an exposure suitable for tuberous Begonias if that helps. In cool climates they have wide tolerances but your summer heat would kill them without some protection.

I don't think you can keep them in pots, especially not in the summer. They will be better off in the ground.

What about a pot outside that can be covered when needed?

Not sure I understand the question so let me paraphrase: you want to grow it in a pot, and protect the pot?

That will be hard, because in South Carolina your winters are too cold and your summers are too hot. Fuchsias are mostly from parts of the world with equable climates--"springlike" all year. F. magellanica ranges further south than most, but it comes from a cool-temperate rainforest climate similar to that of the Hoh Rainforest on the coast of Washington.

You could protect the pot from frost, but how will you protect the roots from heat in the summer?

That by the way is probably the leading killer of Fuchsias in the South: when the temperature rises beyond their tolerances, their chemistry shuts down. They turn lethargic, and then diseases like Phytophthora (which thrives in hot, humid weather) come along and finish them off.

In the ground you have a chance, because their roots will be cooler--especially if you mulch them and keep them out of afternoon sun.

Although not particularly common, people grow Fuchsias in the Central Vallley of California where it's hotter than blazes in summer. They do it by keeping them shaded and giving them water to compensate for the heat. Of course California isn't humid in summer so Phytophthera isn't as common as in the southeast.

Good luck and have fun.