I think a tighter consistency is going to be more important for long-term storage/aging. For instance, 70/70 is a good mark to aim for, with as little change as possible. If this is a storage-only box, then opening it regularly for a cigar to smoke, disturbing the ambient conditions therein, won't be a problem.

If you're talking about a humi you're smoking from most of the time, then some fluctuation won't matter or even be noticed. Conditions in my humi go from probably around 58-65% rh and from 65-78 degrees. Which is cool, because a cigar from a 70% rh box is usually too wet to smoke. I've never noticed the temp to make any difference, unless it's the temp in a car on a hot day. Also, from that same box - an igloo cooler - I've seen cigars develop plume, which is supposed to be a sign of a well-aged cigar, having been left undisturbed for a relatively long period. These were Fuente Anejos, with the fluctuations described above. But they were in a cigar box that I left closed.