I opened the door a little bit and was listening to him breathe and he is wheezing quite a bit. No mucus that I can see yet.

In the early sign of a RI, if it is the case you will not always notice the presence of mucus.

Your BP might have been sick for quite longer and you are just now noticing it, it is very possible.

Anyway no one can give a diagnosis online, however since wheezing is not normal for a BP and is one of the signs of RI all I can do is to recommend you to consult an herp vet, here is how to find one in your area http://www.arav.org/USMembers.htm

Meanwhile you can bump your temps as well as humidity

Mayby he's just got the sniffles.
You've got to be kidding