There are plenty of muskie rivers and lakes near Ct. One of the NYC reservoirs had tiger muskies, Muscoot if I recall correctly was one of them.
Then there is the Delaware River. The NJ state record muskie came out the huge hole below the Delaware Water Gap bridge on Rt. 80.
Greenwood Lake on the NJ/NY border is good enough for muskie that there are actually guide services for the fishery. Other NJ lakes are stocked with muskie and the Hacketstown warm water hatchery raises muskie.
Both Pa. and NY have plenty of muskie lakes and rivers. The St. Lawrence River is world renowned for muskies as is the upper Niagara River from the Peace Bridge to around Grand Island. Pa. has huge muskies in the Kinzua Reservoir in northwestern Pa., the Allegany River system downstream to Pittsburgh, the Susquehanna River (both branches), and other major impoundments and rivers.
Anyway, that is a few spots off the top of my head from years of fishing all three of those states.
Waters in Ct. that would support muskie are Candlewood, Lilli, Zoar, Lake Housatonic, the Ct. River and most of the larger drinking water reservoirs.
Muskie aren't stocked here because it is another expense and the focus is on the pike program. The best bet for a DEEP muskie program is for an exchange deal like Ct. swapping kokanee fry for some muskie fry with another state. Ct. has an exclusive with kokanee here in the Northeast and New England and could leverage deals with other states for walleye, muskie and channel catfish. But this requires thinking outside the box and government agencies don't do that well.