currently have jd's, danios, plecos in a planted 125 acrylic outside. just set up this tank a few weeks ago so it's a work in progress. no problem with cold so far, we'll see what happens in summer with the heat!
have a canoe converted to a pond that has a few plants, but no fish yet. it's aluminum so the temp drops quickly even with heaters.
at our motel we have an old fiberglass skiff that we set up as a pond 4 years ago and it's doing great. plants grow like crazy, except water lillies, too shallow. have jd's plecos, chinese algae eaters, platies, paradise fish, danios, guppies and probably a few that i've forgotten. we run 3 x 300w heaters in the winter and water temp is never below 60.
how about you? what do you have setup?