A better way is to put a few containers filled with water in the fridge and leave the fridge power on. It doesn't cost too much power since nobody is going to open and close it.
As for water, you may need to have somebody to come to your house and flush toilets from time to time. You toilet water seals will dry out after sometimes. When this happens, the smell from sewer would go through your toilets and fill all your house. So, shut off water is not an idea.
