I bit the bullet and upgraded tonight after my PC told me it was going to start the upgrade in 7 minutes anyway. Funny thing is, I have my laptop connected to a 24 inch monitor, which wont show anything on the screen since the upgrade, and I haven't touched any of the connections.
I believe in Win 10 if you are using dual monitors ( PC screen and external monitor) you have to designate which is the "main" screen. Should be a tutorial out there.