What I can't figure out is why he can hold it through the night, but can't wait more than 5 minutes after he wakes from just a two hour nap, or after playing for a half an hour. Just trying to figure this out is enough to make anyone crazy
LOL - the answer to that one is actually very simple. Like every other mammal on the planet (you and I included), your puppy can hold his bladder longer overnight for the simple reason that his body is not producing much urine at that time. You must have noticed that you can happily sleep 8+ hours without having to get up and urinate. Bet it's the first thing you do in the morning though

And you wouldn't have a hope of going all day long without a potty stop - or at least, not without significant discomfort!
Well, it's the same for a puppy. Night time is deep sleep time - the body's growth and repair phase. During this time, non-essential bodily functions such as urine production
slow down. And since not much urine is being produced, naturally, none of us need to get up in the middle of the night to pee. If we wake for any other reason though, and also first thing in the morning - well, first task is to empty the bladder.
And that's why you can't compare how long a pup can last overnight with how long he can during the day. The two things are just entirely
unrelated. During the day time, urine production is full steam ahead, whatever the pup is doing. Therefore, he *must* empty his bladder more frequently. Especially after/during periods of activity (it's a stimulant) - so now you *know* he's going to pee after or during playtime, you can predict it - get him outside after 10-15 min activity.