Data with tethering

[hdelagrange]

I'm planning to go to Italy for a few weeks. I want to:
* use tethering from my Android tablet to 2 smartphones and an ipod touch;
* be online without watching the clock,
* have at least 1 GB;
* do not need to call;
* want a hassle-free experience;
* need good coverage since I want to use the tablet or a phone that is tethered to it as gps;
* pay around 25 euro, if possible less...

That would bring down the options to:
WIND: Mega Unlimited
TIM: INTERNET 5GB per Tablet
Vodafone: Sempre Super

Correct? It is all very complicated.

I also have a Tre simcard that still works, so the option of SuperInternet is also possible which is really cheap. I remember the coverage of Tre to be just acceptable (unfortunately I could not stop my own mifi to roam so it was almost unuseable), but I'm afraid the coverage in rural areas might be not that good (going to Puglia inlands). Any ideas on that?