Same answer on the Hunterdon end. Parks close at dusk. I have seen people walking dogs with flashlights there and I've never seen the Park Rangers bother them, so I gotta imagine you'd be fine. But, yes, technically, there is a county ordinance prohibiting it.
Before the storm CT was graded and pretty much paved with cinder dust. I call it the Ho Chi Minh Trail, it's so flat, smooth and wide. At times I've ridden it at night with no lights, (not on purpose,) and it is pitch black, but it can be done; it's just not any fun. Any cruddy commuter light is probably adequate as long as you don't go too fast.
I live in High bridge and we ride the trail at night a lot in Winter. The ride from HB to Long Valley and back riding tempo at night with lights is great fun. I am aware of no prohibition. If there is one it is not enforeced.
be careful with parking, check for signs at the lot about being closed after dark. If you park in the lot and the trail is not "open" at night, you could come back and find your car has been towed/ticketed