I wouldn't carry a chain, but I carry and have used a spare master link that is appropriate for your chain. I would skip the spare quick release. I carry and have used spare bolts when some holding the rack jiggled out and were lost. I have carried a little tube of blue locktite ever since, which may be an over reaction. I definitely use the locktite when installing the rack. Personally I don't carry spare cables, but I would recommend a careful inspection before you leave, especially of the brake cable near the fat end in the levers. Look for broken strands. Also check any cable stops in the brake system, I have had one disintegrate which leads to a total failure of that brake.
Some judgement on what to take is required, the answer varies depending no your tour location and the ease of getting new parts.
Ahh, I almost forgot, some latex gloves for messing with the chain.
I would add chain lube to the list.
I know you are not flying, but if you were you would need a pedal wrench, I use a short one as a compromise.