It will need a cool root run with acidic soil. Same conditions as heaths and heathers. Probably not seeing too many of those there, either. What about evergreen azaleas, can you manage those? If so, the rhododendron might live for awhile, given similar treatment.

No, I don't recall seeing a lot of heathers around. Evergreen azaleas on the other hand are fairly common. I've got five or six. They're all from box stores too, unfortunately, and they weren't really labeled when I bought them, so I don't know what particular cultivars they are.
Actually, I'm thinking of keeping the R. impeditum in a pot and just moving it around to the optimal site based on the season, like I do with the vireyas. I can give it sun during the cool spring months and give it shade and shelter in the summer and winter.

If you can raise Vireyas you can raise impeditum. Vireyas are tropical rhododendrons from Borneo and northern Australia.

R. impeditum is hardy to -15F so will need protection from winter cold and winds. One of the best dwarf rhododendrons, this species has a tight compact habit with attractive silver-gray foliage. Bright blue-purple flowers make a nice contrast. David G. Leach, in Rhododendrons of the World, suggests an excellent use for it: "This is an ideal species for the rock garden, in the forefront of a shrub border or as an edging for beds. You might try covering it with straw in the winter. Never fertilize after it blooms, wait until the following spring. It may not need any fertilizer anyway. It normally takes full summer sun.

Well, I haven't killed any azaleas or rhodies yet, but I don't have a lot of experience either. I think I'll keep this one in a pot for now though, maybe kind of a quasi-bonsai.

I am not sure why "keeping in a pot" is considered good. If it means that you will move it in winter to a protected location, then I see your point. But otherwise being in a pot exposes a plant to more extremes. Terracotta pots will dessicate the soil. Dark colored posts must be kept from getting direct sunlight or they will fry the roots. They are always freezing and thawing in winter unless they are heavily mulched. In general it is difficult to raise a plant in a pot. They is why big box garden centers have trouble keeping potted plants alive.

Well, if I plant it out in the garden I'll forget about it. Also, then I'm forced to choose either a sunny spot that bakes in the summer or a spot under deciduous trees that is hot and shady in summer and sunny when it's freezing cold. I tend to have better luck with more demanding plants when I can move them around in response to how they look. I think I'll keep it in a sunny place outside in the Spring, keep it shadier in summer with the vireyas, then bury the pot in mulch during the winter along side my bonsai. If that doesn't work, then it was probably a lost cause. I saw on a website that people have trouble keeping this species alive in the Charlotte area of North Carolina. Our summers are comparable, possibly a little hotter, so I'm not too optimistic about making it happy out in the garden. If I can move it around depending on season, maybe it'll have a chance. Or maybe we can just move to Oregon; many of my plants would be much happier then.

Big boxes here have trouble keeping plants alive because they don't water them - not that it isn't also true that the south side of a little black plastic pot cooks when the sun hits it.

You could keep yours as a pot subject for decades by moving it up into larger pots and giving it fresh potting medium to grow in.

i can see the attraction...pretty little shrub.
i have planted them 2 or 3 times(purchased locally from the same chain you mentioned) and they did not like it down here. just had to try, though. i really like the foliage and flower colors.
that same store has also been known to stock plants such as colorado blue spruce. i'd like to see one of those in a landscape here, too, but probably ain't gonna' happen.

Well, I'm too don't have a good experience with impeditums.
Being successful in growing over 100 different rhododendrons, azaleas, pierises and kalmias I unexpectedly found than impeditums need something else than their relatives. What is that 'something' still remains undetermined :-(((
For the past 3 years I planted 6 of them in a different parts of the garden and only 1(one!) survived so far. The sole survivor had been planted in a slightly raised bed where native clay was almost completely substituted by forest soil with heavy leaf mound (mostly oak's) content.
I'm still inclined to find what does it really need to prosper since I could have a lot of use for such beauty.

One problem with R. impeditum is that its roots are just barely under the soil. All rhododendrons have shallow roots, but R. impeditum's are proportionately shallower because it is such a small plant. And to make matters worse, since it is such a small plant you can't mulch it as heavily as other rhododendrons. Hence they are subject to the roots getting too hot, too dry, and too cold. Probably not too wet.

rhodyman ,
This is a reasonable explanation.
Thanks.

Eukaryote, I've tried R. impeditum here in z6b middle TN, and it's not a terrifically happy camper in my hot, humid conditions. We typically have a 6 week droughty period in late summer hereabouts, and it hates that, even with regular watering. Plus the water here comes from a limestone aquifer and runs about 7.3 pH, which doesn't help.

Your screen name gave me a chuckle. Using it that way struck me as a clever internetly pun -- hey, a domain name you don't have to pay for! Maybe I'll change mine to Archaea, although it doesn't describe me well except for the fact that I'm getting on in years.