I wouldn't worry about putting insulated pots over in-ground bushes for the cold. Blueray is hardy to zone 4b and Legacy is zone 5. I rarely have much winter dieback from my blueberry bushes, maybe a small tip here or there amongst all of them, but not enough to harm them. For the rabbits and deer, though, yes, a pot can be helpful in the winter to protect the tender tidbits, but I prefer a bunny wire cage year round for tiny, tender plants when critters are in play. (My poor Bluegold gotten munched almost to the ground the fall after it was planted. It was a set back, but it's recovered and is almost big enough to fruit now.) The pictures in the original post look normal for new plants adjusting to their environment, particularly if they were mail order, as they had to endure shipping as well as climate and soil changes. Not getting bigger in the first few months is also normal. (I prefer to pick up my plants at local nurseries; you can get a bigger plant that's used to your climate for the same price as the mail order plants.) It sounds like you've moved them to a container now, since you mention bringing them in? I find containers more difficult for blueberries, particularly overwintering. I had a TopHat die wintering in our screened-in porch; we're not sure if the pot was too wet over winter, got too cold, or something else - it wasn't worth figuring it out, we just pulled it and put something else in the pot (probably a tomato). I now have two Sunshine Blues in pots that I picked up on clearance last year. They overwintered in the basement (around 50°F). (Hardy to zone 5 but that's risky for a container in zone 6, and they have shorter chill requirements than northern highbush, so wonky weather can bring them out of dormancy early.) They need very little water during their dormant months. I think they only got a tiny bit of water a couple times all winter in teeny tiny pots (I don't recommend that part.) They looked terrible when they went into the basement; they looked okay when they came out of dormancy, and they are lovely small plants now ... not big, but healthy. They are in potting soil since they are in containers. If you've transplanted yours into containers, they should be in potting soil, not top soil. Potting soil is usually around a 6-6.5 in pH (most will say). Mine claimed a target pH of 6.2 and I made no amendments for the Sunshine Blues. (My other bushes are all in-ground northern highbush.) When you transplanted it into the pot, that is a setback to the plant's growth. (You started over basically.) If you include new pictures we can give better advice based on the current state of the plants.

Looks like these lovely people have already given you pretty good diagnostics and advice, but I just wanted to mention one other thing. Southern Bluebelle is a southern highbush variety of blueberry. They come out of dormancy much more readily and earlier than northern highbush varieties, so you run the risk of losing your flowers (and thus berries) to late frosts and freezes. I picked up a couple Sunshine Blues last year and overwintered them in my basement ... they ended up blooming down there with the freezes around here going through Mother's Day (honestly, I was worried the weather might get my northern varieties berries this year, but fortunately they bloomed late enough to get pollinated and berry); one of them did throw a couple more flowers early June. Also, Southern Bluebelle lists a hardiness of zone 6-10; I hope that yours are planted in a more protected area of your garden, since you list your zone as 5-6. If you end up having to try again with blueberries, you might opt for a northern high bush variety. I grow Jersey (enormous plant at this point), Northland (a halfhigh, so smaller, and extremely cold hardy), and Berkeley (plant is still young but shouldn't be nearly as big as Jersey, though not small); I also have a Bluegold (supposed to be relatively compact), but it has suffered mechanical (deer) set backs that, so I can speak to its normal but it hasn't died despite its abuses. There are many varieties, though, so you can pick for features you like.

The penultimate part of your second post establishes that you are asking about a compact horticultural selection rather than the wild parental species. A tightly branched evergreen shrub with bronze-colored new foliage that matures to a glossy dark green. Throughout the year, older leaves turn brilliant red before dropping. Scented creamy white flowers develop into ornamental, blue-black, olive-like fruit. Ideal for use as a hedge, screening, or foundation plant. Shogun Series Little Emperor Japanese Blueberry Tree (monrovia.com) A new and distinct cultivar of Elaeocarpus plant named `Monproud`, characterized by its upright, columnar and compact plant habit; relatively slow growth rate; short internodes and relatively small leaves; dense and bushy plant form; and elliptically-shaped, undulate and twisting leaves that are initially bronzed green in color becoming dark green with development. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=PP17611.PN.&OS=PN/PP17611&RS=PN/PP17611

Anyone familar with Japanese Blueberry? We are considering using them as an informal hedge..