Upvote:5
I traveled by ferry two weeks ago.
Wifi is available to buy if needed and if you have a cabin, then its free. it was ok for light browsing.
There are power connectors available, though best places seem to be taken
yes i was able to access car deck serval times (there was a posted timetable when it is allowed but i went whenever i needed and that was fine). Just ask the receptionist for access and you can go. My car was on top deck, not sure if it was different for below deck cars.