After many failures, I tried again, and....
I *can* enjoy cold tea. Not quite iced, in this trial, but cold. It was 100 degrees today and I was not enjoying my hot tea as much....
I started with some nice Alishan Oolong. I put the dry leaf in my cup, added cold water from the tap, and put it in the fridge for about 6 hours.
Then I drank it, and it was good!
I think the key was the quantity: instead of using more tea per volume of water than I would normally for hot tea, as I've often seen suggested, I actually used the same, but it seemed like less.
For a 16 oz cup, I used the amount of tea I would normally use for my 2 oz gaiwan, about 1 gram, keeping in mind that this particularly lovely tea will easily yield 8-10 infusions from that quantity in the gaiwan (making a total of 16-20 oz of hot tea). So I used the same amount of tea that I would use to make that volume of hot tea, but since it was not done gongfu style and was brewed in the cup, it looked like a lot less.
Happy camper, me!