Heating Detached single care garage

[97audia4]

Looking for some recommendations on heating my single detached garage for central Pa winter/ fall. I only have 120v out there with no way of adding 240v with out a huge expense.

There are two 5" diameter vents on the front and rear near the peak, and as you can see only half of the garage is insulated right now where there is storage and I am not sure thats the best way to insulated but it was there when I bought the place.

Dimensions are 11x19

Ideal temp would be 65 degrees

 

[D45]

How do you heat your house.....propane or natural gas?

How far is the garage from the house?

What about a small kerosene floor heater?

 

[97audia4]

How do you heat your house.....propane or natural gas?

How far is the garage from the house?

What about a small kerosene floor heater?

house is force air, with an oil furnace. House is about 40 feet from my garage, the neighbors and people across the street have natural gas heat so the lines are near by but not sure what it would cost to have it in the garage or if there is a 120v natual gas heater worth buying.

Picture of the vent, there is the same on the back side of it.

 

[thickhead]

Seems like a direct vent propane heater would be a good way to handle this one.