Forget the binary of duration vs. seasonality for travel savings; the real question is flexibility. Neither a fixed duration nor the low season guarantees the best prices if you're not agile. In Japan, last-minute offers for onsen during the week can be unbeatable, regardless of the month. It's your ability to go on a whim, not a pre-set number of days, that makes the difference. Spontaneity is the best strategy for tight budgets, not the calendar.