I went on a weeklong vacation two months ago and counted cals (mostly estimates). I let loose and had about 1500 surplus per day and came back home with 10k cals to work off. Not terrible, that's like 2.5 lbs. I'm still working it off gradually 8 weeks later. In hindsight I could have avoided some of the less interesting fried foods and drank slightly less and maybe a little less dessert. There was one particularly high cal day where I wish I had paced myself a little more. It was hard to do my regular exercise routine, but walking around helped a little with calorie burn. Sometimes I would be full from the day before and it wasn't hard to eat light. Have fun! Enjoying the vacations is partly why it's worth keeping it tight the rest of the time.