I have stayed in a few hotels as a vegan.  I try to make sure to get a room with a refrigerator and microwave or access to a kitchenette.  I mostly premake meals and pack them along.  But I might bring some dry oats or couscous, cinammon, and packets of stevia, maybe some rasins.  I just have to add a little water to the oats or couscous in a bowl and microwave them and add the stevia, raisins, and cinammon for a nice hot breafkast.  And have a mango or apple or banana on the side.  Another filling snack/breakfast is a soft tortilla rolled up with a nut/seed butter inside.  Or vegan fat free refried beans and salsa and a leafy green in it.  

Dishes I make ahead and keep in a cooler or the refrigerator: sauteed tempeh, fresh pineapple, and brocoli over brown rice or millet; vegan potato salad and/or coleslaw; chana masala over millet; red lentil dahl over rice; garden salads with beans, fruits, veggies, tahini dressing; tempeh cabbage saurkraut sandwiches and roasted sweet potato fries; falafal patty mix (from Fantastic Old World); homemade soups such as vegan split pea, black bean tomato and veggies with hot spices, vegan chili.  Premake a bean dip and make some homemade bread and have bread and dip and microwave some frozen vegetables on the side.  I eat lots of raw fruits, raw vegetables that keep without refrigeration such as cauliflower, carrots, snap peas, mushrooms; raw nuts and seeds to snack on while out and about, even raw whole dates.  I bring along smaller cartons of plant milks too.  I sometimes make my own energy bars or muffins ahead of time to have on hand for snacks or breakfast.  Hope this helps!