I don't know if I agree with the others or not. We got our puppy at 3 months and did not leave him water while he was in his cage. Now we weren't gone alot either. Starting in August he was alone 8 hours when we were back to work. He had someone letting him out one time in the day, but we still left him no water because he was having accidents. We now leave him water because he is able to hold it. He was not deprived, or mistreated. He was having accidents and the water was causing it. He was given access to water once while we were gone and I feel that is enough while you are training.

You need to do what is best for your dog and in your situation, no one can tell you you are wrong or right.