My flat is near Montmartre, 10 rue Nicolet 75018 Paris. It is near Lamarck Caulaincourt (line 12) or 10 minutes walk from Anvers (line 2).
My flat is a small two room appartment on the first floor, is very calm, in Montmartre next to the Sacré coeur, and there are all the convenient shops you need nearby (chemist, bakery, supermarket, post offices, wine bars..). I live there so there will be food in the fridge, you're free to help yourselves.
2 people can stay but as I've said it is a small flat so you need to be organised :)