Just curious as to the choice of DVD's for backing up. Most have moved away from them for many reasons, but the primary reason is their lack of longevity and unreliability long term. While there are some "archival" cd's that may hold up, most DVD's are rated at 30 years and I've seen them fail in as few as 5 years. Not criticizing your overall concept, intriguing thought process.
Not that there is a good solution, as hard drives have issues, cloud storage is nearly impossible to use because of the time it takes to upload the information.
Personally I'm looking very hard into and testing SSD drives as possible long term storage. Since each drive will probably only be written to one time, there is little chance of the drive causing corruption, and because of the nature of the way the data is recorded onto the drive, I'm not sure there is any thing that can degrade the data over long periods of times. A little pricey, but I only keep the finished stuff on it, the rest is backed up through a 3 tiered series of raid 5 devices, one which is stored at a different location.