I’d say anything over a 6500 sq ft home is a pain in the ass. You already have 2 rooms you don’t use at 6500 sq ft. I’m in these houses a lot and don’t see the point beyond having room for a gym/workout room, a bar, game room and office. Those all fit very comfortably in 6500 sq ft. Perhaps if you have like 5 kids, then go up. 

 I have a lot of kids lol 

 Good. More kids, need more rooms. Just using the experience of the people I see who live in these homes. Most of them are professionals/lawyers/doctors who either have no kids or 1-3 kids. Most of the rooms are just there being potential cost factors when they go to sell.