Most hotels at least have a mini-fridge. I travel a lot and I always check and some hotels will give you one (or charge a very minimal fee) for both a fridge and microwave.
Nuts in your purse are good as well as some string cheese for a quick snack. Also, jerky (watch for sugar) and pork rinds. Also, maybe a small can of tuna (with the pull tab lid) and a couple of packets of mayo for a quick tuna salad. I've also made pepperoni chips which I love. Preheat your oven to 350, place pepperoni on a bake sheet in single layer and bake until crisp. Watch these as they go from done to burnt pretty fast. Seal in an airtight container. I like these for the crunch. Also, they are sort of salty which will encourage to drink lots of water
Most of all HAVE FUN!!