My wife and I have burned practically all points in our DL accounts. Currently, DL only offers a 48 hr. window from time of booking award to purchase of same. In our case, given that we would only consider F or J, that would involve depositing a minimum of 250K points from our Amex or Marriott accounts prior to ordering award tickets. This would be necessary in order to avoid any risk of point transfer outside of the 48 hr. window. Do other airlines have such a similarly narrow window? DL previously allowed 14 days. We can consider any airline allowed under Amex or Marriott plans.