Take the pack and play to the campground for moments when no one can be 100% hands-on with the toddler (and expect it to get filthy - it's outdoors at a campground).
I also wore one of the hiking child backpacks with my child in it at that age for hikes and just around the campsite sometimes. He loved being up high where he could see everything. (you can google Kelty Kids to see what I mean, they are expensive from Kelty, but I've seen them in 2nd hand stores and on Craigslist).
Otherwise, they need to plan on spending a lot of one-on-one time with the toddler. They should NOT plan on a lot of time hanging out and chatting with the adults. It is not going to happen.
For you in general, one of the funny things about camping is that every time I go, I am surprised at how dirty everyone and everything is and how quickly that happens. And then I remember that this is part of the fun, and I have to let images of cleans hands and faces go, and only worry about washing up just before we eat. Relax and have fun!