Easy answer (to get the job offer, anyway) when asked "We sometimes work long hours. Are you OK with that?" I answer, "I've pulled 80-90 hour weeks (just last year) & luckily my kids are old enough that they don't need much attention on weekdays or weekends. Also, (to emphasize my "partying days are over" advantage), my friends don't drag me into as much nonsense as they used to."
Once you get the job (although, I highly recommend you avoid taking a job if you get a death march software plantation vibe), you manage high demands by nailing management on requirements and milestones and then out-plan and out-deliver your work so you have an answer for "hey, why are you leaving when we're all working overtime?" If you put in overtime at the start, assist other people and show you can deliver, then they can't give you much grief later.
Once you get the job (although, I highly recommend you avoid taking a job if you get a death march software plantation vibe), you manage high demands by nailing management on requirements and milestones and then out-plan and out-deliver your work so you have an answer for "hey, why are you leaving when we're all working overtime?" If you put in overtime at the start, assist other people and show you can deliver, then they can't give you much grief later.