My wife and I are celebrating our sapphire wedding anniversary today. We are both introverts (she's probably intj) and we've been delighted to be on our own all day! Got up a bit late, pottered into town for a coffee, had a good lunch at a smart restaurant, spent the rest of the day mooching about at home doing our own thing. We chat a bit, then wander off on our own, then watch a film, then wander off a bit more, read a bit. No pressure or expectation, except which film to watch. We are lucky in that we both like the same sort of places and activities (and lack of activities !). Being with her is being on my own in company, and I'm sure she finds the same. There are problems - neither of us makes friends easily and if one of us were more extravert that would be less of an issue. I need more affirmation and contact with other people than she does, and I need practical and emotional support when my wife is unwell (she needs constant medication for chronic anxiety) - but experience has taught me to be cautious because there is a very narrow gap between too little and too much for us and it's not always easy to control.
Can't say it's the only way to do it, but it's worked for us through all the ups and downs of life. I don't think I could have coped with an extraverted partner - I'd have probably gone into please-you mode until I imploded.