Sorry to hear about your kitty -- those decisions are never easy.

For just 36h, it sounds like an automatic feeder could work well. You'll want to decide between those that rotate/open up a lid to expose the food vs. those that dispense food from a hopper. I like the former because my cat gets a measured amount of food. However, the other kind may be more suited to your needs depending on whether your cats are accustomed to free choice feeding and how many feeders you plan on purchasing.