Get an x pen. Put his crate inside the pen. He will have 6-8' to play around.
My baby loved his pen, but he was very well potty trained. I know with Yorkies it's so hard to leave them. Yorkies need their people. I would NEVER get a Yorkie if I had to be away to a full time job. If you have to be away for 6 hours or more have you thought about a pet sitter or pet walker? Check Angie's list.
