How to use single tape per day in an LTO library?

I have a HP LTO tape unit. I set up partitions, one for each day of the week, use tape 1 for Monday etc. To simplify things a little, we run full b/u's daily and rotate the Friday tape offsite. Our system works well for our environment. In your case, where the latest b/u must be off site, you would still be able to use a partition scheme and export the tape from the unit and replace it with another as necessary.