As far as bathrooms, four would be ideal, but they could survive with three if they had to.
至於浴室,4間是最裡想,但是如果只有3間,他們也能勉強湊合著過去。
survive 在原句中不是 "存活"的語意,而是日子依然過的下去`。
3 [intransitive] to manage to live a normal life even though you have very little money
survive on
I don’t know how you all manage to survive on Jeremy’s salary.
the amount that a family needs each week just to survive
http://www.ldoceonline.com/dictionary/survive