Mike,
The maxima x ventricosa should be tollerant of those conditions, but this is speculation.
From personal experience, I can tell you that fusca and, beleive it or not, hamata are pretty tollerant, and should be able to adapt. I grew both of those on my deck last year, and my conditions (summer) were:
day 85-95 ~40% humidity (but it rains more that SF, so odd days are >90%)
night 55-75 (yes, big swings depending on weather) ~70% humidity
As you can see, we really don't have a set weather pattern, and the two plants (along with aristolochioides, sanguinea, truncataxventricosa and some others) all did pretty well.