Erin, indulging isn't a major problem: just do what you can on the trip and go back to paleo when you can - it might be when you get home.
While I primarily try to avoid high-carb foods at friends' houses (if 'paleo' is too much to wish for), I remind myself that I spent my entire life eating that way, and that I'm going to spend the rest of my life eating this better way. A few days of of some extra carbs aren't going to hurt me more than they already have. The wonderful thing about paleo is that it's self-sustaining - it's almost easier to get on the wagon than to fall off it!
If I'm concerned, I'll bring along some nuts (even though not 100% paleo-kosher according to some) and a jar of coconut oil to protect from getting too hungry/distracted/vulnerable. Sardines are good except rather obvious (I stopped eating sardines at work for that reason - and the oil from the can was splattering on my white shirt...)
At meals I take extra veggies or meat. If I have rice/potatoes it's just enough to avoid "discussion" - and most of that gets left on the plate anyway. I put lots of olive oil on everything.
What I mostly get is lots of questioning because I lost a bunch of weight and "look great" :-)
As an aside, I find it interesting to see what happens when I DO eat carbs (for me the most dramatic shift - the paleo angle is a more recent icing on the meatloaf). Birthday cake is a great example: If I'm celebrating with friends/family, I usually have a small slice, and am surprised at the sugar rush which is for me a wave of heat and a hyper feeling. I don't feel inclined to have more (this is huge for me - I used to sneak four or five or six big slices after the first one!) But if it's a not-special office party and someone leaves out a cake for self-serve, I don't indulge (actually, the end of my cubicle desk is the office pastry spot - and I have zero problems with that).