In the T’Pring case, we also see that sex isn’t the only outlet. A fight to the death is just as effective, with Spock ending up not needing to bed T’Pring, having resolved his Ponn Farr by fighting Kirk.
While the cultural custom is a fight to the death, it is possible that some form of extended, high-stakes physical combat might be enough to relieve things, but Vulcan sensibilities might simply prevent them from choosing that as an option.