Talk:European Union/@comment-2A02:120B:2C64:2150:6914:3775:302F:4546-20180209165746/@comment-25229736-20180212204940

I have good experiences with Vodafone in Portugal: they seem to be the cheapest for prepaid data and have excellent reception. Moreover, they have a small shop in the airport. Most of the staff is bored and in a down mood, but if you are proactively friendly, you might make their day.

The period in which the operator can monitor your usage and may possibly conclude that you are 'permanently roaming' is four months, so you would be ok. If the operator of the simcard you buy would not offer you free roaming (which they can), the price should not be higher than €7.7 per gb, which is a reasonable price.

See this official statement.