Also people who aren't technically minded might only know "kWh" as that's what it states on your power bill and they can directly guess what kind of energy bill this fridge might cause.
So you are technically correct I guess and we all know that's the best kind of correct.
We do have worse stuff in the metric system though, kcal is not the same as the SI for energy (J) for example. Also everything involving time gets messy quickly. Nothing compared to the imperial measurements obviously
As others have said private boats are probably the best bet, but there are also sailing cruises which cross the atlantic, I believe the Alexander Humboldt stationed in Bremen makes that trip once a year. There are also other ships that I forgot the name of. It is really expensive though