I'm tempted to see how this would work out. I still have a grand-fathered plan so no worries of an overcharge, but battery issues might be a problem. Is this practical? Using an iP4 on 4.3.5 non-jailbroken. No Bluetooth accessories, either.
"Practical" is a nebulous term. Your question is pointless. Use all cellular data for a month if you want to; I don't see why it would even matter if you're willing to put up with the slower speed and you have the unlimited plan.