Lady started out only outside trained since she was my first little dog. I was able to train her to use a pad by the door in a pinch while I was at work or if the weather was bad. Then I was in a bad car accident and wasn't able to take her out so I trained her to use the pee pads 24/7. I became a believer and now couldn't imagine not having a little dog who wasn't at least cross trained. Lady is a Maltese and I don't know if they are worse about bad weather than Yorkies are, but Lady does not do rain or snow.
I started with disposables, but have switched to washable pee pads. I started with Pish Pads and invested $150 in a roll including shipping. What a waste of money IMO! They get stuck together by the plastic backing in the washer and start peeling away and tearing pretty quickly. You can't bleach them so they get really stinky really fast. I ended up throwing the pads I had cut off the roll away after a couple of months. I have part of a roll left that I have no idea what to do with as I wouldn't use them again.
I have since found out from many others on another forum that they have had the same problem - they don't hold up and they STINK!
These people recommended Pooch Pads to me and I have been much happier with them. They are very well made, sewn together, and you can bleach them. I would really recommend them.