Remember you can always do body weight exercises no matter where you are! Push ups, squats, lunges, sit-ups/crunches, run in place, etc. Make a 20 min routine and you'll be doing great! If you have it, take an exercise band so you can do a lot more upper body stuff (biceps, triceps, back, shoulders).
Are you driving or flying? If flying, try to stock up on some of the things you like when you get there.
If you're driving, stock up on things you like that are easy to eat (use a cooler for things that need to stay cold). I've done this many times and it works really well.
Nuts
Bananas
Apples
Oranges
Pears
Baby carrots
Cut up veggies
String cheese
granola bars
Protein shakes
Protein powder and shaker
Pretzels/crackers
Single size peanut butter
Dried fruit
Water
Like the previous person said, many fast-food places and rest-stops now have fairly decent salads and snacks.
Remember you are in control!
