You go to REVISE -- oh you are going away.
Just go to each listing and End it.
Since you don't have a Store you will have no fees.
The listings will remain in your Unsold List for 90 days.
If you will be away longer than that, you could Relist all the items, paying the fees for one day listings and close them again. There is a chance that someone will find them and buy, so do this with your fingers crossed.
Then the unsold items will go back on the list for another 90 days.
But frankly, I would cut and paste all the descriptions with HTML coding to a text document and store it on your desktop until you return. The items may well be stale by then anyway.