Have fun on your vacation! I don't count calories when I'm on vacation either and I'm only partway successful with the making good choices (clearly something I still need to work on). I went to Mexico in February and I can tell you that there were a lot of margaritas consumed on that trip! Margaritas don't fit into a diet so well.
But it ended up being a good experience. I knew I was going to go off my calorie plan and I knew it was going to set me back in terms of weight loss, but it was worth it to be able to relax and enjoy my vacation. It's clearly slowed my weightloss, but I think being able to take a week off here and there for a vacation or business trip helps me stick to my diet the rest of the time.
The really positive thing was that, although I sure didn't lose weight and it was a couple of weeks before I was back on track in that regard, I also didn't gain weight. I was really worried about this. I remember stepping on a scale during the middle of the trip and being so relieved to see that the number hadn't gone up. Seeing that I could increase my calories without immediately gaining all the weight I'd lost back has helped me feel more comfortable that I'll be able to increase my calories when I get to the maintenance stage. Hopefully that will be your experience, too.
I did manage to fit some exercise in every day and I've made this a part of all of my trips. I find that exercising helps me relax about the food that I'm eating so I can enjoy the vacation more. But it sounds like you will be getting lots of exercise (esp. chasing a two-year old around). Did you know that, depending on your weight, you can burn upwards of 300 calories an hour by hiking? At least according to a couple of different online calculators I use (
http://www.healthstatus.com/cbc.html is one of them).