My advice would be to not upgrade as I did it (I'm using iPhone six and standard phantom ) and to be honest I don't know how I can access flight without upgrading, because it gets in the way of the operating system, anyway now the remote control doesn't link and as somebody else said, it's only to protect cold weather operations. With regards to the original poster my previous software allowed 1080 recording at 50 or 60 FPS but to be honest I preferred 2.7 K and 25 FPS it produced a better result.
Can I wish you all a turkey like non-flying Merry Christmas!
Ty