I think you have an excellent goal. My hockeyboy is grown up, but I am on the road with skatergirl about one long weekend a month during competition season. This is the first season I'm doing it primal (well, primalish).
MissJecka had great suggestions. If you find yourself at a fast food place for a meal, Panera and Chipotle have decent options. Even McD's offers salads with meat. None of that is top quality, but at least it's closer to what you might eat at home.
I always travel with a soft side cooler filled with drinks and DDs favorite cut up fruit and veggies. DD isn't primal so I may pack her a sandwich to avoid the crummy meal options on the road. I also pack her some kind of protein bars. I don't pack Pop-Tarts anymore, lol. If we're lucky, there's a frig in the hotel room. If not, I'm refilling the ice every day. I generally eat just 2 meals a day on these trips and snack only on fruits and veggies. When we're in a restaurant I enjoy the heck out of those meals! Most of the time, I can get something pretty primal.
When you get back, you may be bloated and heavier. In my experience, it's almost always water retention from restaurant food. My weight magically drops back down in 3 or 4 days.
CW-125, part calorie counting, part transition to primal
GW- Goals are no longer weight-related