" My interaction has been primarily limited to in-house patent attorneys, and they don't seem to work appreciably harder or be more stressed out."
This is definitely true, but that is precisely the difference between biglaw and in-house.
biglaw has worse-than-startup hours.
in-house is basically 9-5.
(though i've been called at 1am on my wedding anniversary before, it is basically the only thing that happened in 10 years)
There is a significant paycut associated with in-house as a result, of course.