OK, here is my take on it. ARE YOU NUTS!!!!!
When I went in Feb, I brought my 5 kids, my niece, my nephew, my friend and her 2 little ones.
Let's just say it was not as smooth as we planned it. The 2 teenage boys slept in a tent outside. My friend's ds2 was into everything. He plugged and overflowed my bathroom sink. Turned on my water pump when my fresh water tank was empty. Kept sliding my slide in and out. Kept turning my water heater on and off and from electric to gas. (can you tell he likes buttons?) Finally I found a couple of buttons to let him do. The light on my bed and the little button that turns the power for the antenna off and on, it even has a little green LED that came on and off. My camper was always full of sand and my goodness it was crowded. He also woke up one night and cried for 2-3 hours because we could not find his cup. She brought him out to the van so as not to disturb everyone. We were very aggravated because the next morning we found his cup in the hamper. It had not occurred to us to look there. I love her and her kids, but if we had not been close it could have ruined our relationship. Luckily after the first couple of days her son realized that I am not as nice as his momma and my discipline is rough. He finally only messed with the buttons I appointed him.
We brought another niece another time and it was fine. And my niece and nephew this trip were great, well except my niece is a bit of a diva and takes forever to get ready.
They really helped out with the little ones and my friend and my laundry. Could not have done it w/o them.
If we ever do have someone come with us again, they will have to be in a tent of their own (or ours if we have one), but I will not share the camper again except for a niece or nephew that is old enough to fend for themselves.
Fact is that you don't know how it will be sharing close quarters with someone until you are there. Luckily, since my family is so large, extra people coming usually is not an option.
Oh, there was one trip where we met up with the inlaws at a campground. They stayed in a condo and we stayed in our camper. 2 nieces bunked with us. Trying to do what we wanted was horrid. Trying to get the whole group together and ready on time. I knew this about them so had planned it so we arrived days before them and left days after them so that I would not be aggravated about them ruining my vacation. I considered the 3-4 days they were there as THEIR vacation and went with the flaw even if we missed everything planned. I then spent the time alone with my family doing what we did not get to do with them. This is kind of the mentality you have to take when traveling with others.
OK, I know you weren't asking for a novel, so I will shut up now.