I have no water on hand. I would have to go to the LFS with my 5g jugs for water in an emergancy, I have 8 of them...in the middle of the night, I would be up the creek.
I have two 37g plastic cans for FISH ONLY that I use for water changes, I would salvage what I could from my main tank to those tubs so the critters could live...if there was a slow leak.
I have no room for storage, no basement, not even in the garage, which would freeze anyway.
I have learned the hard way to not putts with the tank in the middle of the night when all the stores are closed.
I work night shift and it is easy for me to start something in the middle of the night.