So far I've got 10 of them and planning to add 15 more. I provide a densely planted aquarium and the fore ground is clear for swimming space. The water has a pH of 6.5 and is relatively soft. They will definately lay some eggs in this tank, but as you guessed the parents and all the other fish will feast on the eggs and any fry that happen to make it. You have to feed the the smallest of foods for the first week, thn you can use microworms or baby brine shrimp.
Cardinals are a tough fish to spawn.
If its not that far you could go ahead and have some water sitting in a container so it can age, then all you'd have to do is move the fish in about a 5 gallon bucket. If it's a long way, you can try to get some one else to age some water for you. Actually if you can keep the filter bed alive you just about have it made. Fish are tough and they can take the bucket treatment for a day or 2 with no problems. There is a small possiblity that the gravel might cause a leak in the tank with all the bumping around on the trip.