What you always can do is get one of these UMTS-WLAN routers.
For example:
http://www.amazon.de/Huawei-E5-Mobil.../dp/B003SZ2TIA
(sorry for the link in german)
Its a mobile UMTS/WLAN hotspot.
It can be used with the iPad wifi as well as other devices. Its fairly cheap and you can add your favorite dataplan as its unlocked.
Could be useful for you now especially since you already bought the iPad Wifi