My husband is permanently on a PEG and he uses 5-6 cans of Ross Twocal HN at 475 cal/can, 2 cans 3 times a day. It goes easily down the tube and can be ordered from Amazon by the case with free delivery. His nutritionist recommended it. We have traveled to Hawaii and Washington and it is no problem. We sometimes order the food to be delivered right to the hotel if we are going for more than a few days. In a pinch, he uses Ensure, just takes a few more cans. We used to get the 2cal from Apria Health care, which is all over the country and you can get a state directory if you want to get your supplies from them while you travel. You can get a letter from your doctor to carry with you so you can have a few cans of formula for air travel, but we never really needed this. He just takes 2 cans right before we go to the airport, or even at the airport before going thru security. Then he is good for several hours till we land. You can take an empty water bottle to fill with water so you don't have to pay big bucks after security for their bottled water. Just fill it at a fountain.