TP, my FRiend, TP...
My gold.
Someone always brings up toilet paper and I get to write my solution for having lots of wet cloth like cleaner that cleans the bottom better than toilet paper, is flushable if you still have working plumbing, and is cheaper if you get Walmart brand Wet Wipes, and takes up little room for storage for four people for a year - A WHOLE YEAR.
I have two boxes with these cleaner packages stored inside and the storage boxes are not large. I'm trying to remember, but I think the total cost was something like $40. Toilet paper takes up a huge amount of room to store for that many people and I don't have that much room. Now, I don't need all that room - just the two boxes that are easy to store.
You are right that toilet paper/wet wipes will be valuable.