DH, three kids, two small dogs and I lived in an RV for 15 years. When we started the job that required RV living our kids were 11, 8 and 6. When we moved back to our property, still living in the RV, they were 26, 23 and 21. The older one had married and they still live in a RV. We have been building a house for the past 7 years and we're still not finished. However we are living it the house and it's mostly done.
When living in an RV with that many people, you have to learn to "rotate" :) You must learn to get along or you will all go nuts. We are still a very close family. We homeschooled so the kids were there all day, every day. Rainy days are the pits. We often lived in very muddy places.
Some of our best memories are from those 15 years. If you ave specific questions, I would be happy to try and answer them. We would be gone 6 months at a time between visits to our mobile home that we had lived in. We took tons of food with us because it was difficult to find the things we liked to eat "on the road".
Best of luck with your adventure!