Unfortunately, I relied on the information above to my loss. If you want a seat assignment you MUST book directly on IcelandAir - DO NOT BOOK USING JetBlue. I booked on a JetBlue/IcelandAir flight 2 days ago for a flight 5 months in future expecting I could get seat assignments. After calling Iceland Air they said I could not receive seat assignments until I physically show up at airport just before the flight. I reached to JetBlue to cancel and try to book on Iceland Air, but they said they could only give me a voucher since 24 hours passed. I have a family of 4 and would like to sit with them and not worry about an overbooked flight.