Crates are a great idea and I do have one for Mika, though she rarely uses it. She tends to share with my other dogs who have their own space under the stairs. There's no door just a baby gate, the floor is linoleum and they have blankets and bowls in there. I only tend to lock the gate if they need to be out of the way while the back is open for instance! I have three dogs so they all entertain each other, Mika still plays with me but when I've had enough there are two other willing playmates!!! Is getting a playmate out of the question? What better excuse for another furbaby!
If another dog is a no no how about a kitten? If your yorkie is still young or well socialized you shouldn't have a problem!
They will still need to carefully introduced though!