A plot worked the same way every season exhausts itself; a plot re-staked every season is lost. Series here are kept alive the way good ground is kept: the boundaries never move, and everything inside them rotates.
Rotation is planned in the changing line, not in the card. A season of sittings shares one light and one setting family, so the frames sit together; the next season changes the light, the hour, the wardrobe palette — while her five staked lines are pasted word for word, untouched. The contrast between seasons is what makes each one readable as a chapter instead of a blur.
Keep a short season record beside the card: the changing lines used, the frames kept, the one frame that fronts the season. When a later season disappoints, the record says whether the ground or the weather was at fault — and it is almost always the weather, which is cheap to change.
Move the weather all you like. Never move the post. That is the whole art of a long series, and it is mostly patience.