Geez, Princey, there are actually loads of fish you can keep in cold/cool/temperate water. There are many Asian fish (mainly cyprinids) i.e., goldfish, koi, some barbs and danios, some varieties of loaches, fish from North America, parts of Europe.....
Many fish are not commonly known due to the popularity of "tropicals" even tho some "tropicals" do quite well in cooler or unheated water. Others are quite familiar but not always thought of as tolerating lower temperatures.
Even with ponds, you can keep quite a few popular types of fish in container ponds or garden ponds for the summer so long as the temp doesn't drop below ~65, 55 or so. (depending on fish) Even in New England, I have an astounding # of guppies vacationing in a 45 gallon container on my deck with some Mollies. My rosy barbs are hanging out with Mr. Big (pl*co) in my upper garden pond, with koi and goldies below in the main pond. The gups, mollies, barbs and Mr Big will be coming in for the winter as well as some of the goldfish.
What do *you* like?