I’ve been feeding my friend’s cats for the past week. As she was due back from her holiday this evening, I put the keys through her letterbox after I had locked up today. Unfortunately her flight has been cancelled and she won’t be back until Sunday evening. What do I do?! I’m most concerned about them not having enough water. Would it be crazy to pop some ice cubes and food pouches through the letterbox?! Or, will they be okay until Sunday?