If you want to buy anything on a Monday when everything else is closed, come to the Coffee shop of the village. Of course it is a men's spot, but inside you can buy biscuits, chocolates, etc etc.
I don't think anything else is open during the winter months either! It is this coffee shop only.
No newspapers, or cell phone cards, but the people are good hearted, and they will smile if you ask to take them a photo. Usually, locals expect you to greet them and the majority of them speak English.
It is good to show that you respect them. I am sure they will offer you a drink if they understand that you are open to them.
I visited the village of Lofou in March, and I spent 2 nights here.
On Sunday the village was full of people wandering in the beautiful cobble-stone alleys, and it was full of life even on that rainy day.
On Monday however the village looked like haunted. It was just me and some locals at the kafenio (cafe) of the village. Oh yes...and some workers constructing some houses!
You might feel really lonesome in winter but it is worth visiting this village and walking through its narrow alleys. Here is the beauty and you will really enjoy it.
Be sure to have your camera along, and flat shoes.