The only way I see that working, after Kim has made such a big to do about hating all of them is if she stays in Paris (is it,

) and does scenes there, the way Carrie did when she went to Paris with Mikhail Baryshnikov, and we saw her life there, meanwhile the rest of the girls were in NYC.
OR they do something like when a production films "twins" in the same scene, but it's really the same actress playing both parts and the two characters are spliced together into a seamless scene. Like the movies,
The Parent Trap. They just green screen where Kim is supposed to be sitting or standing with the rest of the cast. Then she comes in later and films her part in the scene alone, without having to talk or see anyone, and it's all spliced together in the editing room later.