Wouldn't worry about that 1GB per day thing, seriously unless you're streaming movies (I'd wager you won't get connection fast enough to do that, even if you wanted to) then there's no way you'd use that amount in a day
That's more than my usage in a month here - and every weekday I browse news sites and "flipboard", send messages using imessage, check out facebook and receive e-mails at work. I say all that just as an example of what can build up data usage.
This of course is relating to phone data usage, not if you take a laptop, that might be considerably more.