FBinNY 

I don't have any fixed list, and even if I did it might not apply to your situation. The key to my tool and spares list isn't in the particulars, but in the thought process.

The first step is to prevent problems by choosing equipment with reliability in mind. Since I'm not racing, I don't sweat the last few grams and, for instance pass on carbon seatposts and handlebars and opt for the proven reliability of aluminum.

However, I still ride tubulars as I have for 40 years, trading some reliability for comfort, though it isn't as bad a trade off as one might think. In the event of a serious glass cut, I have a complete tire vs. just a spare tube. On multi-day solo trips I carry 2 spares, but when riding with friends we each carry only one, figuring we can cover for each other if needed.

The next step is to consider scenarios, what can happen, how likely, how serious, and what can I do while on the road. I balance that against the weight consideration. For instance, I carry only those absolutely critical tools that aren't available everywhere, such as a cassette lockring tool, but figure I can always beg or borrow the wrench to turn it with.

Also the rules are different if I'm in an area where total self-suffiency is necessary, such as Northern Maine where I may not see another human for days, vs central Pensylvania, where I can always hitchhike to the next town.

In your case, I'd carry a hanger on a multi-day trip because I wouldn't want to wait around for the correct one to be overnighted to me, but for a weekend road trip, I'd leave it home. Either way I'd be sure my derailleur was 100% before leaving.

One other things friends and we did when we did long tours, was arrange logistical backup support in advance (this was before Fedex) with someone back home, who could locate emergency spares, and get them to us, by mail or Greyhound bus. I've Greyhounded entire replacement bikes to friends who's bikes were totaled in a crash.

So as I said, it isn't a matter of a list, but of considered planning.