I just booked Pop with Orbitz at whatever the already applied discount was (it was the same price as a FL Resident rate through Disney), plus a 15% code. I did it through the app, which CLEARLY states FREE CANCELLATION, while the website does not. I took screenshots, but my confirmation email also states free cancellation. Plus, I got an extra 2% Orbucks using the app.
I've booked through Orbitz before, when it was advantageous, and have had no problems. There is no reason that your reservation should be cancelled because of how you booked (barring any major unforeseen circumstances)
You can search night by night to get the per night price. It's not exactly convenient, but it works.