Not sure what you should do about local backups, but I think you should consider off-site storage in additional to whatever local backup plan you come up with. If you trust cloud services (or the videos are not too sensitive), you can sign up for something like CrashPlan which offers unlimited backup to the cloud. It is a pain transferring that much data back and forth from the internet, but the idea here would be that the cloud backup is your "last resort" in case something happened locally.
Enough with backups. Now for the fun part: set up a Plex server and have it catalog your videos. Then, stream them to any device that you own. Instant enjoyment and easy of access for all those old videos.