Relax, you're doing a great job of smoking slow and enjoying the experience.
I typically have smokes that last from one to two hours. Pipes are funny, a bowl twice the size of another one, doesn't last twice as long. It's maybe 1.5 times longer. My mid size pipes all can give very long smokes, depending on the cut of the tobacco. I have a little bitty MM Huck Finn cob, that I only smoke compressed tobacco in, and it easily lasts over an hour too. It's chamber is so small that I need to use a pipe nail to pack it with.
As several others have written, the quality of the smoke doesn't degrade in a pipe, if it is left unsmoked. I've come back to a bowl two days later, fired it up, and carried on right where I left off.
So..... I think that you are to be congratulated on your smoking method. I don't believe that a regular size pipe can be smoked 'properly' in thirty minutes. It would have to be getting really hot if it were.