Thanks for giving us the chance to help you. By "250" do you mean 250MB ?
Ok, can you tell me, what type of usage, you want to do on that trip, like listening to online music, uploading pictures on facebook etc.
No, remote support is only for PC. Can you clarify your problem once more, do you want to know, why the data is consumed even if you turn off the data or do you want to know, how much data you will need on that trip ?
See, data can be consumed by many things on a device, every app on the iPad need data to run properly. So, you may think that how data get consumed when you use FB for 2 to 3 mins, this is the reason for the data consumption and when you check FB, every word and picture you see on it is downloaded on your device. Now, if the data is off all the day and you only turn it on while checking your FB account then, the problem must be on the service provider side. Can you tell me, how do you check the data consumption, like by SMS alert or message from the provider etc. ?