In a previous relationship, she could only orgasm from about 15-20 of direct and constant clit-licking, so foreplay, giving her an orgasm, her getting me going, and then sex was about an hour to an hour and a half. Actual penis in vagina? Maybe 15-20 minutes if we changed positions multiple times. I like to do that to expressly increase my staying power, as staying in one position only is a sure way to only last about 10 minutes. The longest time of actual intercourse with her was about 35-40 minutes, a few times, but that very rare.
With the woman who is now my wife, we once had sex 5 times in 30 hours one weekend. She warms up very quickly (and wants me inside her) so foreplay is usually only 5-10 minutes at most! Two of those 5 times were 30 minutes or so of actual fucking, we both were getting tired, so I actually stopped before cumming. I was hard the whole time, and I usually have to fight off orgasm after 10 minutes of continuous in-and-out, so that was a rare feeling of being able to fuck for a long time.
None of the women I've been with needed marathon length single sessions. After resting for a bit, we would go again if we felt like we needed more. Most times, we just fell asleep in the after-glow.