This is why break away hangers and/or mounting bolts were developed. How's the rear der and/or chain. Sure looks like the usual scars from a der cage getting tangled up in the spokes.

If/when the worst case happens the repair would be to replace the complete drop out. If you truly like this bike and want it to last as long as possible you'll begin the hunt for a replacement dropout (and of course the easily replaceable hanger). But do know replacing a dropout is not a simple plug and play, IF you could even source a replacement. While you are looking for a replacement also contact a few carbon frame repair shops to see the aprox replacement labor costs (as they are currently...). Assuming you are able to find a dropout and learn of the aprox total cost (shipping 2 ways? and/or labor to dissemble and reassemble the bike?) you can make that financial/emotional decision on values. IMO the repair is not likely to be "worth" it unless the emotional value is great.

The failure mode of these types injuries tend to not result in catastrophic events. Rear wheels lock up in the frame and one skids to a stop is what I would expect. This won't kill you but you might have a long walk back. A cool story later unless when on a costly vacation and you either don't ride any more on it or would need to find a bike rental. Andy