Conner took almost a full year to housetrain. He goes outside in his pen, plus is walked every day. He would be mortified if he went in the house. And my husband thought he would never be trained.
I think what did it for Conner was taking him to my mother's house in Florida. They also have a yorkie, and Conner would see Liberty going outside and he loves Liberty and wanted to imitate him. Once it clicks inside their heads, they are good to go.