I believe Labyrinthine married two different INTPs and it didn't work out in the end. (EDIT! I forgot that labyrinthine no longer identifies as an INFJ though!) Cafe (who used to be here) is married happily to an INTP. Violaine (who used to be here) also told me she was a fan of the INFJ/INTP combo (she was an INFJ), but I'm not sure what personality type the guy was that she ended up having kids with. EJCC's parents are that type combination. The typology writer AJ Drenth is an INTP married to an INFJ and they are great partners professionally.
I think all type combinations can work if the two people are committed to it, and if mental illness is not a huge factor in the trajectory of the relationship. However, there are certainly combos that are probably easier than others. I don't think practical matters are either of these two types' strengths (particularly making money!), so that could put stress on the relationship. This may be anecdotal, but I know several people who have transitioned after marrying someone and in each case, they were NTPs. I think that particular type is more able to talk themselves in or out of wildly different possibilities, which can be charming, but also can be upsetting to INFJs who tend to value consistency. I think the attention of an NTP can also be kind of feast or famine. They are very varied, interesting folks who know a lot about many different subjects, and intellectually are incredibly stimulating to INFJs, which is a big part of their appeal. However, I think they also get bored kind of easily, and can have difficulties sticking with things for very long. I think sometimes it would feel like being on your own in the relationship, especially for some of the hard parts. Depending on both parties' personal health, I think they would both value communication and aren't horribly reactive. INFJs are pretty able to look at things from various standpoints (unless they are at the very end of their rope, in which case they can be very tunnel visioned and rigid) and INTPs are kind of flexible in some regards as well and wouldn't get emotionally riled up too easily, so could deal with conflict fairly well if they decided they wanted to. I think maybe with both types, in different ways, they sometimes ignore their wants or needs and don't always fight things out when they should, in a way that can create problems down the road. I think depending on various factors, that combo could become very reclusive, which isn't always healthy because neither would be pushing to go out and interact a lot. I could see an INTP maybe even putting fairly low priority on things like friends or family and an INFJ following their lead but feeling unhappy with the final result. I think both could be creative and open as far as sex goes. INFJs are notoriously dissatisfied long term in relationships and I think part of the reason for that is that they have fairly strong opinions, but also enjoy accommodating and taking people close to them into account and tend to use other's reactions as a kind of echolocation of whether they're being reasonable or not. As a result, it's easy to take advantage of them (knowingly or unknowingly), and if their self sacrifice is not reciprocated, they may become quite unhappy without the other person ever having a hint of their frustration (or at least the extent of it). INFJs are also kind of bad at knowing and articulating what's going on internally with themselves until the feelings are quite strong, which could be frustrating to a partner, especially when they are pretty aware of human relationships otherwise. They are more opinionated and honest and have higher standards for people as they become closer to them, which can also be frustrating, even though it is a compliment of sorts that they are being vulnerable in that way or are that invested. I think it might be easy for an INTP to start hiding things from the INFJ that they think they'd be unhappy about and it could cause problems later (financial stuff, feelings, decisions, etc). In other ways, I think sometimes the INFJ could feel their partner was uninvested or that they were unseen by their partner when they got engrossed in something they were really interested in for undisclosed lengths of time. INFJs do need a lot more feeding and watering than INTPs, but are pretty independent when they get that. Some of the INTPs I've encountered are also not particularly interested in gift giving, or in the quality of their surroundings or are kind of cheap sometimes (even the ones I love dearly). I'm not sure if that's just my experience or not, but I think that INFJs, while not necessarily really materialistic or splashy do value quality of things around them, and might be bothered by the lack of interest or emphasis on supplying themselves or others with things that matter. Similarly, I suppose INFJs could be seen as a bit spendthrifty by comparison?
These of course are generalizations, and obviously focus more on the negative aspects of the connection. Maybe it's useful as a jumping off point though? What's your experience, asynartic?