what is the utility rate? base board electric heat is expensive to operate in most places. (The colder it is, the longer you have to run it... the more expensive it will be operationally speaking.)

What is the construction of the breezeway? Block walls with styrofoam insulation, 2x4 with sheetrock? Any windows or exterior doors?

it Is already enclosed with block on the bottom half the room and the windows on top and the 2x4 constraction. There are two screen doors (one on each side). It’s all sided with cedar boards. I have insulated as much as I can.

How do you heat the main part of the house?

Forced heat

Sorry. When I say screen door. I mean storm doors. With windows. The windows in there are nice vinyl

Then you should investigate if it feasible to run duct work to the breezeway.

Do you have natural gas? If so then a gas space heater mounted on the wall may be a solution. A unit that puts out 10-15K BTU should be sufficient. They are many options available, some of which are convection only and require no electricity or external ventilation.

The easiest option is the electric baseboard. This could be 110V or 220V service. The drawback is the electric bill.

Here is what it looks like from outside. Both sides are identical.

I could run a duct from the forced air heat. They whole room is insulated minus the bottom of the side walls.

Never mind.

OK, so just an uninsulated storm door. You'll lose a lot of heat through those.

Maybe I missed it....but is breezeway on a slab or over a crawl space?...don't like the idea of electric baseboard heat!...

It’s just on a slab. I am not looking to spend a lot and I think it would take a lot to put doors in. It’s insulated and all I want to do it keep it somewhat warm in there to keep shoes and coats in there.

I have a similar space between the house and our heated garage. Our house obviously stays warm in winter, the garage is heated to 52 degrees with an LP ceiling mounted unit. so having this in insulated breezeway, with only storm doors and storm windows, kept our shoes and coats miserably cold. I just had new insulated exterior doors and windows put in and we plan to just leave the 32” door to the garage open and are hoping it will be enough to heat that newly insulated breezeway/porch.