'Conversation Piece' is a nice azalea for bonsai. It is is satsuki under the broad definition, if you care about such a label. Parentage is ('Emile Russave' x Carol') x 'Eikan'.
It's a Robin Hill azalea.
More info:
http://donaldhyatt.com/RobinHills/details/ConversationPiece.html
More pictures.
http://www.pbase.com/azaleasociety/conversationpiece
There's nothing special you can do about it. You don't want to roots to dry out, of course. So plant it again where you want to plant them. PH soil should be 4.5-5.5. Azalea root shallow so the root ball is all the roots they have. You don't plant it too deep. Some people even like to plant rhododendron so the root ball is partly above the surface. This helps with drainage, which is important to all rhododendron.
Ideally Japanese azalea have morning sun and some partly shade. In the case of full sun it's an issue of providing enough water for most azalea, though some do get sunburn.
I don't know what the weather is like there currently. But maybe it's a good idea to soak the root ball in an unheated shed where it doesn't freeze. Not using rain water is ok unless tap water is really hard. This is normally always done when replanting rhododendron. Then they can drain a bit before you plant them in your garden. If you pot them then use that to put them inside your unheated shed when it gets colder than usual( maybe 15 F?)
Normally you pull a rhododendron rootball apart to spread out the roots while replanting. But not sure about that now. And you didn't buy a pot bound azalea from a nursery. So probably not needed. Especially if these plants were just ripped out, that would have had a similar effect.
The plants are in dormancy right now and that's also why they may not look as fresh and why they have yellow leaves on the lower branches that drop if you touch them. If this hybrid has that then this is normal. Both autumn colour and deciduousness depend on what traits it inherited. The upper leaves are those that matter. They should not be wrinkled. Well you know how dead foliage looks like.
'Conversation Piece' is hardy to 0 F. But lying around exposed will lower their resistance of course. So yes, winter water the plants but there shouldn't be water in the root ball that freezes into ice.
And cold dry winter wind is what causes problems for most azaleas during winter. The roots should not dry out. It is normal to mulch your rhododendron. If they are covered with snow then that also helps, which is what some wild species rely upon to survive. You can cover them with leaves to protect them further as they will be weaker this year then they ought to be.
As for late spring. You may want to remove flower buds as flowers drain the plant's energy. That way it can focus more energy on putting out new growth. This is normally done at the end of winter but can be done from November to March. For bonsai it is recommended to have only one flower bud on each branch. You can also style a bonsai by having flowers appear in certain regions and not others. Then it is also recommended to remove all flowers, including fruit, once 80% have opened. On top of that it is recommended to not have a satsuki flower at all once every 3 years, maybe at the same time of repotting and pruning.
So it's your decision on how much flower buds you want to keep on and remove. There's no reason to have them all flower. And I don't think there is a reason to remove all of them on all plants. If they survived what they did a few flowers isn't going to kill them, obviously.
But azalea are hardy plants. Some people think azalea as bonsai are not for beginners. I don't really think so. It's just that satsuki bonsai are kind of exclusive and azalea not being trees so some general principles being different.
Thank you for saving these azalea.