For various reasons, last night I went down a rabbit hole of cooking in a hotel or motel room, assuming you have only a microwave, or not even that. What options do you have? Well, even lacking a microwave, your room might have up to 3 different heat sources:
* hair dryer. Probably not hot enough for actual cooking (though some chefs use it to dry out poultry skin before roasting.) But hot enough to melt softer cheeses, so someone suggested it for tuna melts. And could just make food warmer, which can be nice.
* iron. Up to 400 F! There are lots of suggestions or even videos on using this. Wrap your flat food in foil, to keep it and the iron clean, and, well, iron. Supposedly good for grilled cheese, quesadillas, cooking thin meat (including bacon), searing thick meat... Also, if you can safely flip it on its back and keep it stable, it's now a hot plate, for cooking foil 'pans', or an actual skillet if you brought one.
* coffee maker, at least the Mr Coffee drip style. Most obviously it makes hot water (though it's designed to not be boiling water, for the sake of your coffee.) Good for instant ramen, quick oats, probably couscous or bulgur wheat; can make pasta, "boiled" chopped potatoes, "boiled" eggs, though with longer times. "boiled" hot dogs. Poached salmon or eggs.
But it's versatile! You can put veggies like broccoli in the coffee area, and 'steam' them (I suspect a mix of steam and blanch, as hot water and steam bubbles come out). And the warmer under the carafe is a small hot plate... though maybe a week one; one skeptical experimenters were convinced by other uses, but not by their fried eggs. (Maybe scrambled would work better, stirring so everything gets close to the plate.)
Then of course if you do have a microwave you can "bake" potatoes, make scrambled eggs in a mug, even cook pasta or rice (normal ones even, not just "microwaveable").
Getting even more creative: an induction hot plate only weighs a few pounds, maybe you can throw one in your luggage. Or weigh just buying a cheap hot plate, electric skillet (I learned those are a thing) or electric kettle where you're staying; they can cost around US $25.
Imagine a 5 day stay. By living on two burritos a day, you can eat out for $15/day, $75. Or, with a $25 implement, cook groceries purchased at $10/day: $25 + $50 = $75. Same! And with questionably cheap "eat out" and high groceries (though buying cooking supplies for 5 days sucks.) For a longer stay, or with two people, it can lean even more towards buying a tool even if you throw it away after a week or two.
(Though there's also buying plastic cutlery and paper plates, bit of extra cost.)
And if you're making road trips by car then you can have a whole travel kitchen in your trunk if you want.
https://www.myrecipes.com/convenience/foods-you-can-cook-with-coffee-makerhttps://www.onecrazyhouse.com/coffee-pot-cooking/https://www.onecrazyhouse.com/microwave-cooking-hacks/https://www.lonelyplanet.com/news/hotel-chef-iron-cookinghttps://www.wikihow.com/Cook-Food-in-a-Hotel-Roomhttps://youtu.be/VUfjOIprcOEhttps://www.instructables.com/Hotel-Cooking-or-how-to-NOT-empty-your-wallet-eat/