Uncle Al Schönborn from Canada logs several thousands of miles every year with his Volkswagen Golf. If you browse through his photo reports you will see that it is not all flat and straight roads. He isn’t scared by the Appalachian mountains on his way to Florida.
When I started Wayfaring I towed my boat all around Europe with a Hyundai Excel that had only a 1200 cc petrol engine. The only problem with that combination is all our baggage would have to go in the boat. The problem is volume, not power.
A well packed Wayfarer (trailer cover) has little windage specially when it is on a low trailer that, sort of, disappears behind the car. I don’t think power is an issue. Your choice should be based on the amount of gear you want to drag along and the size of your crew (landlubbers included).