Two bottles. One with water (to drink or pour on the neck/head/arms to cool off or wash hands after a roadside repair) and the other with NUUN or similar. Free water in most towns from a fire hydrant/PVC contraption somewhere just off the main street, and there often is water or drinks to buy along the road. I usually stop if it is a kid-run stand…have a chat with the kid and parents/grandparents. Always a good break.