Question : How long do most people stay in Strasbourg?
Answer : Of course you're not most people, but if you were, you'd stay roughly 10 days.
Question : Have you considered flying out of an airport besides Zurich Airport (ZRH)?
Answer : Zurich Airport is a superb airport, but in getting you to Strasbourg, there is a lower cost option – EuroAirport Swiss. It's just 49 miles away and flights are being booked 20% cheaper over the upcoming months.