Pack a secret picnic of her favourite (non liquid) foods for you to share on the flight (for me, it would include some great cheese and crackers, an heirloom tomato salad, some quiche etc). Pop some real napkins in, with a large one to use as a table cloth on the fold down table, maybe a little bud vase with a (probably fabric for ease) flower in it. Get some good chocolates if she likes them, and order your drinks onboard. If you really want to 'up' the experience, have your friends send little (virtual) telegrams for her to read during the meal. On arrival, how about arranging for a friend with a decent enough car to collect you, with a bottle of fizz (if the state law allows alcohol in a moving vehicle - don't want any arrests!) or some favouite soft drinks, snacks etc for the hour's drive. For extra memorability, convince friend to don a chauffer's hat!

With things like this, the thought really does count - and it is going to be far more memorable than a domestic upgrade.