I always got the impression that Vulcan society operated similar to traditional Japanese or other societies where couples were “arranged” by families. Not sure about the one off cases though so maybe there is some kind of sex industry given the physiological toll if it’s not addressed in time
As I recall on Voyager with a little coaxing Tuvok was able to use the holodeck to get “relief” so I’d imagine the same goes for most vulcans who might be on long away missions