Nice pics, thanks for the post. I'm new to growing BOP, so I can't address your specific questions, I have over-wintered bananas and other tropicals indoors for many winters now, and it's common to see some dramatic effects from the shock of being dug up and transported into a less than ideal environment, the goal is only to keep them alive. I hope someone chimes in with some BOP over-wintering advice.

Welcome to the forums and i hope you will find great pleasure in your gardening. It's a continual learning process, so there are wins and losses along the way. First can I say that whichever family member managed to dig up your couple of mature birds of paradise, deserves a medal, because these plants would have to have one of the deepest and toughest root systems! I shifted a baby one once, and it took me a crow-bar and a great deal of sweat! They are often started by removing suckering new plants, but also division. In either process I suspect there is some damage to the root systems, and that's probably what you are seeing now. Please don't worry too much, these guys are sooooo tough that they are almost certain to survive. Just, as you say, its not an ideal time of year, as they won't be in growing mode to recover. I'm sure the problem is only initial transplant shock. Try a couple of doses of seasol, that sometimes helps. Cut off the leaves that are struggling, and as soon as the flowers are past their prime (or do so now - they last well as cut flowers) cut those off, too. The position and drainage you've chosen sounds fine. If there is any chance that they are actually getting more sun than they were in their previos home (even though the tems are getting wintery, the Qld sun is still quite strong) then you might help them "harden up" to their new position by giving them some temporary shade. This could be a bit of shade cloth or even some unwanted other greenery - shrubby stuff, cut off and stuck in the ground nearby to shade them. If you have watered them in well at planting time, don't overdo the water from now on, or any damaged roots that are now recovering, may simply rot. Normally they would not get much rain over winter and they are better on the dry side in that season. Also, don't waste fertilizer on them yet, that would do more harm than good. There's almost no large plant, that will not suffer a little set-back from being completely re-located, we home gardeners usually don't have the equipment or the man=-power to dig up a big enough root-ball to make it that easy. But most plants are also very forgiving, and eager to survive. I think yours will be fine in time, don't stress if they look much worse before they look better, you may have to wait till spring or summer to see an improvement. New leaves, will be a good sign at that time. good luck with them.

My backyard is shielded by many tall overhead trees that keeps most of my backyard shaded all day long. So when you factor in all of the rain we get (along with plenty of good drainage), we have moss growing all over the place; which includes the trunks of my ornamental trees. The green color is just harmless moss that grew on the trunks back at the greenhouses. It will go away all on its own. Especially since Ikea's only been giving them little "sips" of neglectful underwaterings. No wonder they're having leaf problems. On a side note; this year, I've bought myself a weeding tool to rip up these unsightly weeds by their roots. I've been going thru my yard weeding out any that I can find so that the mosses can grow better. Since it looks more appealing, and it's much easier to deal with than trying to grow grass there. Plus, the moss is so much softer to walk on.

It reminds me of a banana tree. Not an expert and hard to tell with it drooping like that, but thought I'd throw that out there. I agree that it is tropical. Also with what others have said, any houseplant that is accustomed to being indoors is going to do poorly to suddenly be put outside. The changes in light and temperature can quickly damage the plant. You have to put it out at the right time, not March where I live, and then gradually get it used to the change in light by first putting it in shade and increasing the amount of sun gradually. And adding fertilizer to a plant that is already stressed, is making matters worse. When you say normally, you keep it in a large SE window. How long have you had it? Was it doing okay without drooping when it was in the window? Did it just dry out and that was when it started to droop? If you haven't done so already, I would do what Flora suggested and soak it at the kitchen sink and let it sit there and drain and then keep it in the house out of the sun until it stops drooping. If that works out, then I'd suggest you bring it to a nursery and have the plant evaluated.