Skyscanner does a very clever thing where if you place a specific query, it'll pass it on to the providers it searches, but it will also cache the result of you

Skyscanner does a very clever thing where if you place a specific query, it'll pass it on to the providers it searches, but it will also cache the result of your search internally and give you estimates for wider-ranging searches. For instance, you can ask: "what's the cheapest flight from Country 1 to Country 2 over the coming year?" and it'll use its internal cache to give you suggested arrival/departure airports and times that you can then combine with local transportation on your own. I'm not aware of any other site that offers this.