I’m not sure that I would group refugee camps on the Aegean Islands in with ‘disaster relief’ (although I understand that this post was specifically about the fire).
I guess that taking this specific event out of the consideration, the two main causes of suffering here are 1. The actual wars/regimes that people are fleeing in their home countries and 2. The asylum system in Europe (and elsewhere, but I am more familiar with Europe). It doesn’t really seem like donating money can help much with either of these (I’m happy to be corrected if wrong, and I haven’t looked into this in enormous depth). Milbig, maybe you could get involved in a group that focusses on political lobbying? I don’t know how effective this is likely to be, and I doubt that EA would say that this is very tractable as a cause. However, I don’t think that the scale, neglectedness, tractability framework is completely foolproof, and it’s obviously very hard to know what is ‘effective’ when it comes to political issues.
A short but relevant article: https://www.theguardian.com/commentisfree/2015/sep/04/help-refugees-donations-government-political-action