I have a boot SSD drive and Time Machine drive internal to the Mac Pro and a LaCie FW800 caddy which I use as a clone (CarbonCopyCloner - free) that I have a calendar entry reminding me to update quarterly.
While the clone is still in the same building, it is in a different room to the Mac Pro. I do not have any business data to put on it, just personal stuff.
If I had anything irreplaceable, I would use an online storage service which you have to pay a fee to use.