So here's my worthless two cents...
YOU have to decide if you can live with what he is willing to give at this moment. That means knowing he is going to be consumed with this until it resolves. Knowing you are going to be his sounding board. Knowing he is not going all in about you where his family is concerned. Do you enjoy your time that you have together, and is it enough? Are you looking at long terms prospects and, if so, can you enure the short term to achieve your long term goals? Is he on the same page with that?
I am coming at this from my own situation, because it is similar in many ways. My SO and I have been together for over five years now. We live an hour apart. I do most of the driving because he hates the drive. I don't mind so it doesn't bother me.
SO also travels a lot. So we spend long spells apart, unless we happen to travel together. But I also travel for work and have my own stints away from him as well.
SO has a vicious ex. Not only did she drag out their D, contesting anything and everything (she basically wanted everything), but she has now hauled him back to court for a Rule 60 request (i.e., "Post-Divorce Relief" - which means she wants more). Just when it looked like everything was finally over.
However, he doesn't talk about it much. Wouldn't bother me if he did because I talk to him about issues with me ex.
He keeps me at arm's length from his family (which is large), and I am PERFECTLY content with that. He is actually protecting me by doing it. He knows I don't like idle chit chat or inane socializing, and that is exactly what would happen. He also doesn't want his sisters (whom he refers to as "a bunch of old, busy body ladies with too much time on their hands") inserting themselves into his life. As the youngest (by 20 years) and only boy, they tend to want to dictate to him, and he hates it.
I've met his oldest DD (both live in other states), and she wasn't exactly the warmest person (which he warned me about as that is her personality), and the youngest one is, well, let's just say that SO doesn't even like her as a person (bends over backwards as "dad" though). SO I would rather NOT want them to know the depth of our relationship. The less they know, at this point, the better! For all his family!
On the flip side, he has met my DD's several times, and my father. But there is not a lot of interaction beyond that. Everyone lives too far apart.
All that being said, if I was looking to get married or something more substantial along those lines, the current set up would bother the hell out of me and I would have to question if it was "enough." But since I don't want anything more than permanent part-time at this stage, what he can give is absolutely perfect for me. I don't WANT his family all up in my business! Ugh! The thought makes me cringe!
The time we spend together is enjoyable, and it is enough for me. As a matter of fact, we have a travel trip planned for later this month as well as one tentative one in February and May. So it's not like we don't spend good quality time together. It is just not being tied at the hip 24/7.
Hence, the reasons I asked all those questions above. Ask yourself to honestly answer - is it enough for you, deep down? If it's not, you need to have a very serious discussion with him about that or resentment will grow, which sounds like it is just starting to take root.