Hi Donna,
I share your worries, believe me!
Basically, the "nowhere" zone means you are consuming few calories (1000 - 1200, say), but are not eating the right ratio of carbs to protein to keep hunger and fatigue at bay. (Many calorie-watching diets fall into this category, and it's why it's so hard for people to stick with them.) So you're right that you don't want to have MF all day and then have a very carby dinner of macaroni and cheese, because you'd never be in ketosis but would be eating too few calories to ever feel full! Yuck!
I think the best thing you can do is to follow the advice of the Success in a Shaker Jar book when it discusses how to gradually transition back to real food when you reach goal. It lays out specific steps for adding back real food a bit at a time; for example, the first week, you simply add an extra serving of veggies. The second, you add a fruit, too. The third, I think you add a dairy, etc. Transition ideally takes a few weeks, but you can condense it if you need to (if you run out of time before your trip, for example). When you are fully "reintegrated" into real food, you don't need to use MF products anymore, but many people do. I know Nancy still eats several MF supps a day to keep her svelte leopardy bod in shape, but she also eats lean and green meals and occasionally has some higher-fat foods, as well.
My advice would be to start with Nancy's awesome November '03 newsletter-- she really lays out what happens during transition, and I think it'll allay many of your fears--
http://www.makemethinner.com/newsletter ... letter.htm
Nancy is the best!
Try not to worry, Donna-- we'll figure it out, with Nancy's help!