My name is Marsha, and I'm 67 years old, with a 50 year old ileostomy. You didn't say if you're irrigating your colostomy or not, but changing alone has never been an issue for me. I went to camp with my ostomy back when I was 16, and used the dark, dank bathrooms to change. Not pleasant, but it worked. I did tell several close friends, so they knew where I was when I changed "off hours". I also hiked and camped......dug a hole to empty my pouch. Back in the day, the supplies were minimal, so you're really lucky today. Since then, I've traveled extensively, snorkled on the great barrier reef, used the holes in t he ground in China & Greece, walked the wall in China, went on saffari in Africa, and road an elephant. My one fiasco was swimming in the dead sea in Israel, where my pouch fell off, leaving me with a horrible mess. But even then, I managed. I just took plenty of supplies, wipes, tape, and tried to think outside the box. Odor is a big factor for me, and I now use Na'scent, which is excellent....and will obscure/ eliminate odor, if you need to change in your tent. The best advice is to be prepared. Sometimes, changing outside, is easier than being cramped up. I've done that too. You might also want to find out if there is an office available.....that you can use if needed.
This is a time for you to explore new places and experience new things, so don't let managing your ostomy get in the way... There's always a way to cope.... Best of luck to you.