I dont think its a good idea to pick up the water at 8... like humans they get thristy... and being so small they can get dehydrated. I know I would hate it if I was thirsty at 8 pm and couldnt get a sip of water for 12 hours
Waking up at night should just be a puppy thing... By 5 months my dog was sleeping through the night without a problem. They will learn to hold it longer and longer.
Especially at such a young age i would rather have her wake me up an extra time than be thristy all night....