Having the Pleistocene (ice age) as a theme for zoos is full of untapped potential… well, save for a certain zoo’s take of the idea when it opened in 2009, but that’s beside the point.
Otherwise, in addition to the animals listed already; there are even more extant species that used to live in Europe in that time period, along with certain species that can be used as proxies:
- Common Hippopotamus
- Brown Hyena - rare in the region’s fossil record, but present
- Wolverine
- European Fallow Deer
- Red Deer
- Moose / Elk
- European Roe Deer
- Persian and/or Amur Leopards - in place of the Cave Leopard
- Wild Boar
- Przewalski’s / Asian Wild Horse - in place of the Tarpan / European Wild Horse
- Onagers
- Domestic Water Buffalo - in place of the European Buffalo
- Barbary Macaque
- Pyrenean + Spanish Ibexes
- Alpine Ibex
- Eurasian Brown Bear
- Eurasian Lynx
- Eurasian (Grey) Wolf
- Domestic (Tauros-type) Cattle - in place of the Aurochs
- Asiatic Black Bear
- Reindeer
- European (Golden) Jackal
- West + East Caucasian Turs
As you can see, there’s a lot more mammals to choose from; and I believe, that with a little creativity, and an execution that should hopefully age better (regarding its collection and quality). I think such an idea can be achieved successfully.