I've ridden the single + trailercycle + 2-children trailer, and the tandem + trailercycle + 2-wheel cargo trailer on all sorts of roads and streets, and quite frankly, the biggest problem is... bike (or multi-user) paths.

If you check carefully your "narrow" bike, you'll notice that you already need about 15-20 inches to clear your legs and 28-30 inches minimum to clear your shoulders and elbows. So a narrow trailer like the Nomad is a tad narrower than you, and a wide one or a 2-children trailer is slightly wider. That being said, you'll have to be a bit more "conservative" when cycling:
– you can't zigzag between cars (even when it would not be impolite or unsafe to do);
– in stop and go traffic, you'll be slower because you can't stop and won't start as quickly;
– you can't swerve around potholes.


As for your wife cycling:
– She probably already knows that some types of skirts are out unless she wants to give a show, but many others can be attached with a clothes pin, for example.
– Riding past midnight in some neighbourhoods might be hazardous, but so is walking to your car in a dark parking lot.
– Some tasks might be difficult: ex.: lifting the bike in her hands to climb to the second floor.