It would surprise me if the leopard fish died because of the cold HandS! Mine have been happy down to 10 degrees still eating and active. How cold would the tank have got?
MCT
Welcome along!
It sounds like you are already getting lots of good advise but I would agree with the need to put your goldies in a nice big tank. My daughter's tank for two goldfish holds 100 litres but they don't need a heater or fancy lights if you aren't keeping live plants. I have a desk lamp on a cheap timer that is directed at the tank and lights it up nicely for viewing.
Good luck with your scheming btw. Money is so much easier to spent than earn! :-?
MCT
Tank Man, you forgot to warn me to have some tissues ready to catch my drool before posting those pictures!
Somehow I don't think I'll ever get a $30,000+ tank though! Do you ever get sent pictures of the tanks once they are set up?
MCT
You sound like a very busy person!
Glad you got your question answered so you can sleep easy at night though. At least until you need another tank for all the fish babies you are going to have!
MCT