I do not have a current backup plan
I would consider getting some external drives and backup yourself.
Ideally you would get 30TB of backup storage.
You could do 30 TB in a raid (15 TB usable)
And then 15 TB more in external drives.
Crash plan is great, but any cloud backup will be slow:
How much can I expect to back up to CrashPlan Central in a day? (CrashPlan for Home only)
On average, you can expect your CrashPlan Central backup to progress by at least 10 GB of information a day, as long as your computer is powered on and not in standby mode.
15TB = 15000GB
10 GB per day = 1500 days....almost 3 years.