As I parent, I don't mind sacrificing sleep for a newborn, but I get a little grouchy in the middle of the night when woken up for any other reason, which brings me to my tip of the day!
Necessity is the mother of invention.
Store a full water bottle in your refrigerator at night and give your older kids full permission to get out of bed to access it for themselves.
That blue water bottle to the right in the picture is a Sport Berkey. The black thing floating in the bottom is a water filter, which allows me to essentially store water in it. The water is filtered as the user sucks through the straw, giving freshly filtered water on demand. Trust me when I say that this water bottle is the favorite in our house. We only have one, and I plan on ordering more because it's just kinda gross to all chug from the same spout!