Can't speak for parent, but for me: on a train (lots of tunnels - no really, lot...

Can't speak for parent, but for me: on a train (lots of tunnels - no really, lots of tunnels[1]), on an airplane and in an airport (no free wifi) -- quite recently.

[1] https://en.wikipedia.org/wiki/Bergen_Line#Line

Side-note, the Norwegian broadcasting service, NRK did a pretty crazy stunt filming the whole thing, and airing it on tv: http://nrkbeta.no/2009/12/18/bergensbanen-eng/