We met a family of 6 that home schooled ( as do we) that had a 23 foot trailer and they were also traveling Missionaries, living full time in the trailer. Kids were all under 10. I was surprised at all the plastic boxes of stuff they had to keep outside all the time so they had room in the trailer for everyone. When they moved and all the boxes were put in the trailer, the family couldn't get in.
So, I agree with the post above, don't get stuck with something that will be too small, It will add to frustrations.
2012 Ford Expedition EL
2016 28BHBE, Surge Guard 34830
2012 26BH (Traded)
2002 Prowler Lynx (totaled due to tire blowout)