Buried cigars?

I live on a slab with no air conditioning. That means that the temps in my house in the summer are not good for storing cigars. Today, I came up with a great (but possibly crazy) idea that I wanted to run past y'all.

I'm thinking about digging a four foot deep hole and inserting an 8" diameter PVC pipe. I would then hang a travel caddy humidor inside the pipe at the depth needed to acheive 68-70 degrees. The top of the pipe would be capped and locked!

Does this seem totally crazy or like a fun and functional weekend project?

The cigars would only spend the hot summer months in the pipe. The others, they would spend in my house at 70*+-.

I need some encouragement/help to move forward.