All that time, you could have been drinking beer instead of just water! Oh well, live and learn.
Over time, you will stretch the neobladder to 400-500ml. You don't want to really let it stretch much beyond that as that is when it starts having problems emptying. That's why it is important to follow the emptying schedule they give you and keep track of output. Your doctor will explain all this in more detail (if you ask) and you don't want to drink too much or too little. If you drink a lot, then your emptying schedule should be shorter, if you drink too little, then drink more.
Hydration is a good thing. You do want to discuss this with your doctor though and give him an indication of your fluid intake and output. Ask him specifically, if "based on your intake" you should decrease the time between emptying to prevent overstretching.
Mike
PS: A few guys have told me that they did the condom catheters every now and then at night when they were getting really frustrated with having to get up so often and never felt rested. As long as you don't jump right to the condom catheter and do it every night, something like that seems to work well for men. You just need to manage it. I use one every night and sleep through the night every night. Since I have to cath anyway and have night time incontinence, doesn't seem like much point in wearing pads/diapers and then having to wake up repeatedly to cath. I wake up with between 600-1000ml in the bag and still cath another 600-800 (or so) when I get up in the morning.
Again, I don't recommend using them long term (unless night time continence never comes) as it is counter to training yourself to regaining night time continence. There are a percentage of us that never acheive night time continence so, for us, the condom catheters are a godsend.