Dongles

Not particuarly the most tech savvy person on the planet, but I understand the basics of a Dongle.

I'm going on two long train journey's on Saturday (booked month's ago) and I'd really like to watch the footy (Asian Cup Final and Cup of Nations).

I've seen pay monthly Dongles, with a minimum of a month contract. Was just wondering how much data would I use streaming two games via Skygo?

Cheers.