The Douze cargo bike looks nice.
The Bike Friday Haul-A-Day doesn't fold, but it also splits in the middle. I'm not sure about the cables.

Anyway, consider how you'll transport everything from the parking garage up to your apartment.

Will you split the bike + trailer (or two halves of the cargo bike), push it all into the elevator, and go up? Or, will you drop half of it, go up. Unload, and then go back for the second half?

I would say one key will be choosing trailers (or a cargo bike) that is easy to maneuver independently.

Good point that a bike + trailer allows flexibility without more redundant bikes... which would be a benefit for a small apartment. I don't have CF, but I've towed a trailer with my steel road racing bike, titanium frankenbike, and aluminum cyclocross bike. I like the Colnago best for towing