Originally Posted by
mixture
You took the wrong approach.
It overwrites the old operating system, therefore the space question is irrelevant !
The space question only applies if you're doing a live upgrade instead of via iTunes.
The review I read (only one of many, I grant you) said the operating system for iOS8 is significantly larger than iOS7. My iThings are over 90% full of apps, music, stuff, etc. I've had the "not enough space" thing in the past, and a right pain it was. I don't need to go there.