I have finally managed to get RW to work with one screen on my laptop, and the other on an iPad. Be happy for me, this has only taken about three weeks to set up.
It's a wired solution, but I don't mind that in the circumstances. One day there'll be a wireless solution.
I had to use an iPad app called "Duet", which is fairly expensive for iPad apps at £12. And as I said, it's wired, not wireless.
However, RW looks really good on the screen and will really help in a few weeks when I need to run my Roman game in a bar where a TV couldn't be set up for me and my players. Fingers crossed it all goes well!