[darrenf]

Ugh, I had no idea about that. Thanks for telling me - doesn't seem like I've received any such message from Three themselves. I'll find out for sure in a couple of days time since as luck would have it I went abroad at the start of this month for the first time since early 2020, and used data without worrying while I was there.

[blitzar]

I havent recieved it yet (I am out of contract > 2 years now) - others who were out of contract got it a few months ago. It appears totally random.

EE have a roaming add-on that may for a cost reproduce the facility, but that was my limited research on the topic, usual disclaimer.