I think there are two possibilities for Amy an…

I think there are two possibilities for Amy and Dan going on the abortion road trip. The first being that she won't have anyone near her to use as a viable support system for something that she clearly hasn't been wanting to do. As much as she probably hates Dan right now, it's better than being alone. The other reason could be him forcing his way on the trip to spend time with her while she does something where she'll have to pay attention to him (if she gives him the cold shoulder initially)

I think you’re on the money there.

Realistically, with as far a long as she is, Amy will likely be having a surgical abortion, which is a more invasive process, unfortunately for her.  So realistically, she probably should have someone with her, at least for the first twelve hours or so afterwards, on the off-chance of a haemorrhage.  Now, to my knowledge, an abortion is a very safe procedure, but surgery is still surgery, so she may not have the option of going alone – especially if she has to drive to and from the clinic.  (Of course, Irish women have been flying back from the UK after surgical abortions for decades, so it didn’t immediately strike me that Amy wouldn’t have the option of being alone. Yet another reason to be grateful for the referendum).

That said, on balance, I would prefer if this was a scenario where Dan forced his way in, because at least that would be him demonstrating on at least some level that he cares about her, and her wellbeing.  (Though knowing him, he’ll probably just claim that he wanted to be sure she’d actually had the abortion, because he is literally one of the Worst Human Beings to Ever Live – I used to say that in jest, now I’m serious).  

Dan’s need to have Amy pay attention to him is one of his character traits that has really fallen away as the show has progressed – in ways both negative and positive.  Think of 1.06, where he is so overtly interested in how she will handle an unplanned pregnancy, or 5.03 where he takes time to savour her reaction to his sleeping with Sophie.  

He’s always been so demanding of her time and attention and energy that his new dismissiveness of her reads really, really oddly.