I guess my best bet is just to make multiple CD backups. I can fit one's year's worth of photos on 4 CDs.
In ten years, you will have 40 CDs. If you make three copies, that will mean 120. If it takes five minutes to burn each one, that's 10 hours of continuous work. So, switch to DVDs. They have about six the capacity... but they take ten times as long to burn. So, it's still a long task.
Optical media, CDs and DVDs, are the best long-term solution we have today. But, first of all, DO NOT use the CDRW rewritable disks for long-term storage; they are NOT long-term durable. CDs are generally better than DVDs for longevity. Properly-stored, writable CDs should last ten or fifteen years. I pulled some church records off of a eight-year-old CD just the other day with no problems at all.
Proper storage is a dark, cool, dry place.
The risk over time is delamination. A CD consists of a thin metal layer laminates to a plastic disk. If the metal layer delaminates at all, all is lost. So, do not label your long-term-storage disks. Certainly, do not put paper, self-adhesive labels on them; over time, the adhesive and paper can deteriorate and contribute to delamination of the disk. Ink is a chemical and who knows what effect it will have over time? So, do not label the disks; label the containers they go in. Do not store them in paper sleves which touch the disk. Over time, the sleve may stick to the disk and as you remove the disk, you could pull the disk apart. Use plastic boxes in which the disk sort of floats. The critical surface to protect is NOT the glossy plastic "bottom" of the disk; the data are not on that surface and, if that surface gets damaged it can be cleaned and polished and restored. The data are on the thin metal surface on the "top" of the disk; so this surface is the important one which nothing should contaminate or touch in long-term storage. The so-called "jewel boxes" are actually perfect for this as long as you do not put a paper inside the top. Instead, apply a self-adhesive label to the outside of the top o the box.
With the disks not labeled, adopt a strict procedure to only have ONE such disk on your desk at a time. In this way, you won't get them mixed up.
Buy high-quality, name-brand disks.
Your idea of making mulitple copies is perfect. Use two or three brands of blank disks so that of one brand does prove to have a long-term reliability issue, you won't loose everything.
Your copying schedule is a perfect idea. With digital media, you do not degrade from copy-to-copy. There have been experiments done on which a copy of a CD has been made, then a copy of the copy, then a copy of the second-generation copy, etc. out to a hundred generations. Then, the hundredth-generation copy has been bit-by-bit compared to the original and found to be 100% exactly the same. I think you can safely extend your copy interval to five if not ten years.
The software you use to burn the disks makes a difference. Also, invest in good, name-brand drives. Finally, even if the disks and drive are capable of super-fast burning, slow it down to 4x. Slowe is better.
