I have done this several times on AA and once with short notice on UA. AA is diffently the best at award redemption on short notice, really anytime. The expedite fees are a pain, I am waived from those, but my wife is not. Our strategy is to use her miles when we plan ahead and mine when we need a short notice ticket on AA.
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dallasflyer, Let's put the fun back in FlyerTalk!