Question : Interested in traveling in the next 30 days and want to get the lowest fare?
Answer : January 1st offers bookings (as of December 5th) that are 25% below the average price for this route. Saving on booking fees means you'll have more cash in hand for the trip.
Question : How long do most people stay in Lisbon when they fly in from Minneapolis?
Answer : Of course you're not most people, but if you were, you'd stay roughly 11 days.
Question : Is price more important than specific travel days for you?
Answer : Friday is your cheapest day to fly in December. Being flexible with your travel days garners you even more savings during your booking.
Question : Are prices changing frequently for this route?
Answer : Flight prices for MSP to LIS change a lot more than most routes. Remember, you can save by booking further in advance.