dieting while out of town

My family and I are on our way to Las Vegas Nevada. We're not going there the same reason most people do, we're going to visit my half brother and my step-brother. I was afraid that while we were in Las Vegas I was going to become frustrated with dieting and give up like I almost did during Christmas break. I figured the only way I can be sure I wouldn't throw in the towel is to figure out why Christmas break was so disheartening for me. I think the reason is that i was trying to eat perfectly, eat only the food I packed and brought with me. When I didn't have the will power to say no to all the amazing food I became so frustrated I almost gave up. I've decided I won't do that while on vacation. I'm going to eat the food I want, but will try and eat in moderation. As long as I don't binge eat the next 4 days I'll consider my diet while on vacation a success. But no matter how I do,  I'll get back on my diet when I get back.