I travel a bunch for work.
If you can get a hotel room with a fridge and microwave you're golden.
I usually buy pre-boiled eggs in a bag and cottage cheese for the week (or just go to store every night or two). For lunch, I'm usually on site at customers place so I go with the flow there. This past week I was near a Firehouse sub shop. I just got the Chief Salad all week with turkey (lettuce, boiled egg, deli meat). I also put a bag of tuna in it (or canned sardines). Sometimes I'll take a bag of pregrilled chicken (like Tyson or Purdue) and put it in teh customers "break room" fridge.
Dinner(s)-- just about every supermarket (Publix this week) has rotisserie chickens or turkey breasts. In the frozen section you can usually find flash frozen salmon, cod, tilapia, etc that is microwavable. Hell, in Maine, the grocery stores will steam lobsters for you for free. Some places usually have shrimp plates on ice.
There's no end to choices when traveling if you have access to a supermarket and a microwave.
Of course, there's always the local BBQ pit or steakhouse or Burger King