Rav Chaim Kanievsky zt”l maintains that in this situation, it is preferable to bake a large number of challos to fulfil the mitzvah of separating challah each time. Rav Shammai Gross (Shu”t Shevet HaKehasi 4:81) and Rav Shraga Feivel Shneebalg (Shu”t Shraga HaMeir 6:16) argue that honouring Shabbos weekly by kneading and baking fresh challah is more important.
R’ Naftoli Kopshitz shlita (Madanay Kohen) just last week gave a shiur on this topic. He concluded that baking challah every week for Shabbos is a mitzvah incumbent upon a woman, taking challah, however, is only a mitzvah if one happens to bake a large enough dough. Since baking challah on Friday is more of a direct mitzvah, that mitzvah takes precedence. (Iy’H we will revisit this topic)
