I'm with you on off-site backups. The usual rule of thumb is to keep 2-3 full backups. At least one on-site for very fast data recovery plus one off-site in case of fire or flood. The reason for a second local backup (father/grandfather) is incase you don't catch that you've changed the contents of a file or it's become corrupted and do not catch it right away. I keep a backup of all of my important data from all of my computers on my local NAS plus off-site backups.
For off-site I use iDrive. The normal price is $70/year for 2TB of personal (non-business) backups but right now they are running a $52/$104 special offer for one or two years of up to 2TB of backup storage. That's all of your home and laptop computers sharing that space. 5TB plans are on special for $150 for two years.
www.idrive.com