Interesting idea, and not easy about the warm ABC species. This is what I could apport:
The zoo would be located in northern Europe, for example, in Findland.
-Their local species would be: Reindeer, Wolverine, Wolf, Moose, Brown bear, Wild boar, Ptarmigan, White-tailed sea eagle, Common eider, Long-tailed duck, Smew, Greylag goose, Barnacle goose, Tengmalm's owl, Black woodpecker, Eurasian lynx, Great grey owl, Red fox.
-Their exotic species would be divided geographically in next sections:
Alpine Highlands: alpine marmot, alpine ibex, wallcreeper, chamois, alpine accentor, white-billed chough, Lammergeier (bearded vulture)
Asian Wonders: Golden snub-nosed monkey, Japanese macaque, Snow pigeon, Red panda, Takin, Tibetan antelope, Snow leopard, Tiger (siberian), Siberian musk deer, Bharal, Markhor, Domestic yak, Himalayan tahr, Himalayan monal, White eared pheasant, Blyth's tragopan, Bar-headed goose, Himalayan griffon vulture, Tanuki (racoon dog), Japanese serow, Siberian crane, Red-crowned crane, Siberian ibex, Zibelline marten, Siberian rubythroat, Siberian salamander, Eastern capercaillie
Canadian Wilderness: Canadian lynx, Elk, Fisher (marten), Canadian beaver, Grey jay, Musk ox, Canada goose, Vancouver Island marmot, American bison, Arctic hare
Patagonian Treasures: Southern pudu, Steamer-ducks, Mara, Vicuna, Magellanic penguin, Andean flamingo, Andean condor, Geoffroy's cat, Cougar, Striated caracara
Wild Australasia: Tasmanian devil, Kea, Common wombat, Tasmanian pademelon, Little blue penguin, Yellow-eyed penguin, New Zealand sea lion
The warm buildings are not a mystery, they would be:
Two heathed greenhouses:
-Amazonian aviary, with roseate spoonbills, scarlet ibis, boat-billed herons, sunbitterns, blue and gold macaws, Brazilian teals, great curassows, toco toucans, white-faced whistling ducks, blue-crowned motmots and green jays. As you can see many of the birds are wetland species, the greenhouse would have a central lake and some watercourses with brigdes for pass over the water.
-Butterfly house, the typical one with the common species kept: Papilio memnon, Siproeta stelenes, Heliconius charitonius, Heliconius melpomene, Morpho menelaus, Idea leuconoe, Greta oto, Parthenos sylvia and a moth, Attacus atlas
Two solid buildings with illuminated tanks in the walls:
-Reptilarium, with the typical commonly available species such as constrictor boa, plumed basilisk, Gila monster, California kingsnake, Green iguana, Collared iguana, Green anole, Giant girdled lizard, Leopard gecko, Corn snake, Radiated tortoise
-Aquarium, that would be a L-shaped building. One of the "sticks" of the L, would hold the freshwater species, and the other, the marine species. On each "stick", one wall would show the cold-weather (mainly native) species, and the other wall, the tropical species. So we would have:
-Cold freshwater (sorry I don't know by memory many of the common names of the fishes, so I will put the scientific only): Thymallus thymallus, Salmo trutta, Barbus barbus, Perca fluviatilis, Esox lucius, Coregonus lavaretus, Anguilla anguilla, Cottus gobio, Lota lota, Huso huso (also some noble crayfishes and a tank with Rana temporaria).
-Warm freshwater: half of tanks for south-east Asia with Danio rerio, Puntius tetrazona, Puntius denisonii, Epalzeorhynchos bicolor, Botia macracantha and other commonly available species. Half of tanks with Amazonian theme, with water more stained with tannines, and with Paracheirodon axelrodi, Serrasalmus nattereri, Electrophorus electricus, Apteronotus albifrons, Cichla ocellaris, Carnegiella strigata, etc.
-Cold marine: Gadus morhua, Trisopterus luscus, Zeus faber, Cyclopterus lumpus, Dicentrarchus labrax, Sparus aurata, Diplodus sargus, Spinachia spinachia, Hippoglossus hippoglossus. Crustaceans too (Homarus gammarus, Cancer pagurus, Nephrops norvegicus. Also some cold water anemones such as Metridium senile, and starfishes such as Asterias rubens.
-Warm marine (Indopacific coral reef) with various species of Chaetodon and Acanthurus and Zebrasoma, Thalassoma, Gomphosus caeruleus, various species of Amphiprion, seahorses, Paracanthurus hepatus, Taeniura lymma, Poroderma africanum, Hemiscyllium ocellatum, Balistoides conspicillum, Rhinecanthus aculeatus, Aeoliscus strigatus, Gymnomuraena zebra, Siganus vulpinus, Synchiropus splendidus and picturatus, and other typical and commonly kept tropical species. Also crustaceans such as Lysmata debelius, Lysmata amboinensis, Stenopus hispidus and Enoplometopus debelius, live corals and gorgonians of various species, and some echinoderms like Diadema setosum and Linckia laevigata.
About the warm-weather animals, I believe that the only way of exhibit them is the same than many cold or temperate-weather zoos choosed for exhibit them: their exhibit having a large outdoor part and a large indoor part where the animals can go when they feel cold. It's not a creative thing, but I can't think in another way. The indoor part of each would be viewable from a glass, but the animals also would have a part hidden from the public view if they want more intimacy. The species here would be reduced to the minimum (5 species) you requested, as I think that the zoo should put the emphasis in cold-weather species only. The species would be lion, plains zebra, Nile crocodile, Bornean orangutan and Malayan tapir. All of them are species that often have this kind of enclosure with warm indoor part. While the indoor would be viewable from a glass, the outdoor would not have glass nor bars, but a high hidden by topiary from the point of view of public, while the terrain inside the enclosure would elevate to public level so one can't appreciate the wall. This is a thing that many zoos already does.
