wrote

A portable trailer-mounted generator has an engine, a propulsion
system for electrons. Would he have to put it on a second trailer
to tow it in Connecticut? Or would the fact that the engine doesn't
drive the wheels be what matters?

I think maybe he should have talked to more than one DOT guy,
maybe politely asked to talk to a supervisor.

Asking to see the applicable portion of the code would not be too much to
ask, and also would help in deciding exactly what other rules might need to
be followed.
--
Jim in NC