CB - It is extremely unlikely that you will be on the same aircraft for your second leg. While you are clearing customs in Terminal B, the aircraft is clearing quarantine, which process takes longer than yours. You will need to go over to Terminal C for your flight to Houston, and even tho it reads the same kind of aircraft, it will be another plane.
The monorail gets you over quickly unless you want to add to the tobacco fumes outside, and then you have a five or so minute walk from one building to the other, just enough for a quick smoke.