Insulation, Radiant and Vapor Barriers - North side of house

I own a house that has the kitchen on the north side of the house. Every winter the kitchen cabinets are so cold they feel like the refrigerator. The kitchen is cantelevered 3 feet and I stuffed insulation in the overhang but it didn't make much difference. The previous owners had the pipes to the sink running through the overhang but I have since moved them into the main part of the basement because they froze up a few times before I added the insulation.
The main problem is in the base cabinets which I assume is due to the cantelever. Is there any suggestions on what has to be done to properly insulate the overhang and/or floor? The basement below the kitchen is unfinished. The house was built in the mid 70's:confused:

There are two issues here. One the cabinets in all houses isolate the heat from the outside surfaces and two your outside surface is increased by the overhang. Closets, drapes, furniture, anything that blocks the heat source will make the area behind it colder.

In all homes, the air leaking out in the upper half of the building is replaced by air leaking in in the lower half of the building. A cantilever provides a good place for a lot of this air to get in and the fiberglass insulation you stiffed in there does little to stop air flow. It may slow it, but you will find a steady flow of really cold air coming in through that space, thus very cold.

I'm not sure what your access is, but you will want to totally air seal that cavity and then super insulate it. A 70's home was probably built with 2x4 walls, so insulation in the back of those cabinets is minimal as well and difficult to improve. Adding a heat source below the floor as part of your modification to the overhang can help.

Hope this gets you started,
Bud

PS, I've never seen a palm tree in NJ:)