Planning and Re-Planning

So my grandmother wanted to meet me for lunch today at Arby's. I said ok, not the healthiest option but I looked up their nutrition menu online and had a whole meal planned out that fit in my calorie goal. Kids turkey sandwich with apples and chocolate milk. I even pre-logged my lunch!

I get there and "oh, we don't have apples or chocolate milk today, is curly fries okay???"

"NO! that is not okay, unless you are hiding some 35 calorie curly fries in there somewhere."

So I frantically search the menu, trying to remember something that wasn't so bad from the website. I settled on a Roast Turkey Salad with Balsamic Vinaigrette dressing ( because when I asked if they had low-fat ranch the girl rolled her eyes and said uh.. it's buttermilk ranch). Sigh.. so I used half the packet of dressing and re-entered my new lunch options.

Everyone says healthy eating is all about planning.
What do you do when your original plan doesn't work out??