I did that trip once. The ferry was the most disgustingly dirty mode of transport I’d ever seen (thinks about current state of own car. Changes I’ve to I’d in previous sentence).
Chunnel has gone out of fashion. I guess it would just confuse a millennial.
More story please. There’s loads you could tell, it just needs prompting. And if it doesn’t make a standalone story, it can add colour to your fiction, or someone else’s. Hint, hint.