Parigi's link will give you lots of great leads.
"seems all the good places are closed". Bof! Certainly it's inconvenient for visitors here for just a few days but, as a local, I find that Sunday and Monday closures are not that big of a deal. There is such breadth and depth to the Paris restaurant scene that you can always find an excellent meal 7/7. I actually find Saturday much more problematic because all my favourite restaurants are booked solid or so frantically busy that service and cuisine suffer.