Kitty Rescue Gone Bad

So for the past few nights an orange and white cat has been sleeping in our flowerbed. The first night I noticed I put an old sweatshirt out there for it. Last night it came back. Jim was checking out Craigslist and a woman posted that her orange and white cat went missing. We thought this was the one, so we called her, she came to check it out, and it wasn't her cat. Too bad! So, after checking the weather and finding out that it was going to get down to 28 degrees F, I let the cat sleep in our garage. I filled a box with dirt so it could relieve itself, we fed it some tuna, laid some old towels and sweatshirts for it to sleep on, and gave it a dish of water. The plan was I would call animal control in the morning so they could come pick it up. Well, animal control doesn't open until 10am, so I waited, then called and found out that they don't do pick ups for cats. So, I packed Tralee up, got the cat in the car, and headed over to the animal shelter, which was only a couple minutes away. When I got there I opened the door and the cat hopped out, and ran away. So. . . all that fuss and the cat is right where it began, only now it might be lost and won't have a nice flowerbed or garage to sleep in tonight. I wish I could be more like Jim and not get emotionally involved, but now I'm worried about the cat. Maybe I should have just let it out of our garage, and let it back in at night for it to sleep. It's getting cold at night now, and I don't want the poor thing to starve/freeze to death. I don't know much about cats, but can one survive ok in cold weather? I just can't stand the thought of it suffering. It was a really nice cat, and crawled into my lap, purred and let me pet it. I tried to do the right thing, but maybe I should have just let it be. I said it a little prayer for it, maybe it can find a nice home. Or maybe it will find its way back to our flowerbed tonight. Who knows. We took a picture of it last night, when we thought the owner was going to come get it. I hope this little cat is happy. . . wherever it ends up.