Some things I do while I travel:

1. Take my own- if I'm in a hotel, I ask for one with a refrigerator & microwave and just bring frozen left overs. Vacations are lovely, but I save money and pain by eating in with the husband.
2. Search ahead of time for restaurants in my destination and along the road that look safe. Call, find their menu, etc. ahead of time. And if it's 5 pm and you've got an option of "well this place is safe, but it's so early" go with safe. Always go with safe. I'd rather eat a granny meal freakishly early in the afternoon that get sick.
3. If you get stuck go to a place that specialises in steak and salad like meals. In my experience they seem to be the safest options. Just make sure not to eat the sauces unless they're obviously gf, and stay away from anything deep fried.

I bring along little containers of sauces I can eat, like any San-J Asian style sauces, Braggs aminos, dressings for salads or veggies. I also plan it out like duckykissy. A possibility is to go to an Asian food restaurant and ask for steamed vegetables and chicken or shrimp and plain steamed rice. Top with your choice of take-along sauces. There are apps available that you can use to search for GF restaurants in the area you are traveling to. If you are in Canada and want fast food, Wendy's has a pretty decent amount of choices for GF. Chili, baked potato (even with broccoli & cheese sauce which is gf), Apple blue cheese grilled chicken salad (without the pecan packet which is dusted with starch possibly from wheat). Chili cheese natchos (not if you are trying to lose weight, lol). You can always order a burger patty to go with your salads or baked potato. They are very accommodating.