5mo Shiba Inu pup Potty Training

Question
Hey, I've had my Shiba pup, Apollo, since he was 8 weeks old.  I've kept him to a very strict schedule of potting and he did very well, even when we moved across country when he was 3 months old.  He is in a crate where he has just enough room to turn around and lay down.  He responds well to sit, wait, shake, down, and up.  I often don't need to even bribe him for him to follow sit, wait and shake.

We have, since the move, had some potty issues.  I assumed that it was a new home and just tried to get him back into a schedule, but it seemed that every week or so, he'd forget for a day to not potty in the house.  After a particularly bad day, I started treating him for a good long potty outdoors.  This worked wonders and I haven't had an accident in the house since, even though he can escape from the kitchen, which is gated. (He did so while I was out last week, he had full reign of the house for over 6 hours and there was not a spot of pee anywhere!)  However, I have noticed that on occasion, his bedding has started to smell like urine.  This is strange, because I have not moved his schedule an inch, the only thing that has changed is I have gone back to graduate school.

Just this evening, I actually witnessed him peeing on his fleece blanket.  I promptly removed it, cleaned the cage and put down some "no go" spray before allowing him back into his fresh, dry crate with no bedding.

His schedule is as follows:

6AM feed, quick outdoor trip, but he never potties then.
8AM walk, we go about 1/4 a mile, he consistently pees and poos then.
Usually, he gets a bit of freedom to follow me about until I am ready to leave and then he gets crated for the day.  I know that there's a limit on dog bladders, but I did an experiment over the past few weeks of pushing how long he could hold it while I was home and the pup could handle the 6 hours I am gone for my orientations.
I get home at 4pm, we go out and potty and play.
6pm we eat and go for a mile walk, this is also the last time he can have water at night.
8:30pm last potty break, then crate for the night.

What can I do to help him realize that it is not okay to pee in the crate? We saw the vet not but a week ago and he has a clean bill of health.

Answer
Small breed puppies have a harder time holding it for a long time, and the fact that he could hold it for six hours one day isn't a guarantee that he can hold it another day, especially if he is napping then waking up during that time.  Also, even though he seems to have a clean bill of health, some dogs can run a low grade UTI that isn't caught without a culture and sensitivity test.  If you can catch some urine, bring it to the vet to have it analyzed just in case if that wasn't done at his checkup.  Also, you didn't mention how old he is, but the rule of thumb is that puppies can usually hold it for one hour longer than their age in months (not written in stone).  Is there a way you could have a dog walker come in at midday for a while just to get him out of the habit of urinating in the crate?