Originally Posted by SouthArk370Z

I wouldn't disconnect the battery from the car as you will lose tuning params and possibly radio presets. You might also need to do a auto-window reset. And the emissions system will reset to a not-ready state.

But none of that is a big deal: the ECM will relearn the tuning after after 15-20 minutes; reentering the radio presets isn't all that difficult; the window reset takes 30 seconds max; unless you plan on doing an emissions test right away it's not a problem - system will be ready after a few drive cycles.
But why have to do any of that when you can just leave the system hot?