If your girl is max skill, +20% will easily satisfy Sophia.
Girl at max xp at lvl 5 gives 60% satisfaction to a level 5 guest. Sophia at guest level 5 requires 90%.
Assuming each room has it's 5% upgrade installed. That's still 25% more needed to
minimally satisfy Sophia.
1 inventory item for each room: 5%
1 room specific card: 5%
1 3 room card: 5%
Temptress card (all rooms): 5%
Socialite card (if holder is resting, all rooms get): 5%
= 25%
I really hope I didn't just embarrass myself by forgetting something
So... if we take Traits out of the math and you're not using the office, you need
every item/card in the game to satisfy Sophia.
And one of those cards has to be on another girl who must be resting instead of helping another guest.
4 or 5 night stay, 3 rooms per day... I'd love to know how you plan to pull that off with only swapping 1 card
Hell... I want to know your plan for doing it with Nora Walsh, who only needs 3 of the 5 items.
And, yes, I know that is an exaggerated example.
Because there is still the 10% from upgraded office and it's highly unlikely for a girl to get totally skunked and get no customer satisfaction traits. Although its very likely a player won't get the one's they want.