I have a family of 8 6 kids myself and wife are TT sleeps 9 comfortably but I noticed allot of the camp grounds state 6 max per site what do large family's do ?
Maybe claim the two oldest belong to the old couple next door. Every camp ground has grand parents wishing come kids would show up for instruction.
Seriously, you may have to pay an extra person fee but I doubt they will kick you out. I think the limit is to control their costa for water/power/trash collection/etc.