The data allowance is pretty low - but if you’re just using it for messaging you should be fine. Start using it to upload vids, pics, or watch youtube etc and it’ll be gone in a few days like other have suggested.
If you’re tech savvy you can change the device IP of your phone or laptop to trick the wifi system into thinking its a different device. On some devices that’s as simple as renewing the wifi lease with a few clicks of the button.
Things to remember as others have said - most hotels have good reliable wifi for free - use that for downloading and uploading anything big. Also, you can get a month pre-paid sim with 12gb of data for about $50AUD (mid 2017) which is a small price to pay for connectivity in almost every euro country when compared to the total cost of your trip.
Hope that helps