Matilda is fine.
Mathilde is heard in my area occasionally, but mostly for older women; perhaps it's time it became popular again. I prefer
Margo to
Margot. As to Euro-chic, we don't have that here!Although I live in a French-speaking area (in Canada) there doesn't seem to be much adoption of names from France..people tend to repeat the familiar names, or use English ones, which are considered slightly exotic. (or exotique.)