Depending on the weather eggs can be kept for up to a month with out refrigeration, so you should have no trouble keeping a half dozen until you use them. Sailors often smear them with a light coat of Vaseline. Some sources recommend turning them over once a day.

Bike touring I don't think you need to do anything special other than trying to avoid breakage.

Also you can just hard boil them all the first night. Hard boiled they keep at least a few days if not cracked. Again, oiling or greasing them may help.