The best method for preparing your printer for a several month period of inactivity, is to install a set of carts filled with PiezoFlush, and do an Initial Fill cycle to purge ink and fill the internal ink system with flush fluid. Our recommended flushing procedures can be found here: http://www.inkjetmall.com/tech/content.php?140-Flushing-Epson-Pro-and-desktop-model-printers-for-safe-long-term-storage-or-when-switching-inks. You will need Windows to run the Adjustment Program to do the Initial Fill cycle.
If you don't have access to a PC, then it may be best to instruct your house sitter to print something about once a week, and remove/shake ink carts every 2 weeks to keep ink in suspension. They will need a little printer operation instruction, like how to print nozzle checks, feed paper, send a print job, remove/shake/reinstall carts, etc...
I hope this helps. Please let me know if you have further questions, or there's anything else I can help you with.
Best regards~ Dana