My almost 6 moth old puppy can hold it for around 6 hours in the day but last night, bearing in mind he had 2 long walks yesterday so was shattered and I fed him at 4, did his toileting trip and bed at 9.30pm but still up at 2.30 for a pee? His last drink was about 7? How can he hold.it longer in the day?? I've also tried going to bed later. Will he just eventually grow out of this??