The taller the vehicle, the more obstacles one might run in to!
![Cool :cool: :cool:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
But, as you plan on having a cabover and are thinking about including a basement under the camper, I suggest you consider a total height of about 12' (before solar panels) rather than the 11' your are currently mentioning. This will allow for a thicker mattress and more room in the cabover, as well as a taller basement for a given camper body height. The extra inches inside the cabover might make things a lot more comfortable.
You might want to consider a cardboard mock-up.
I know you are already avoiding the super-short cabover, but, I suggest you run the number for a 12' vehicle height and decide if the extra foot would be beneficial for you and your family.
You might decide that 11' is tall enough, but at least you would have considered it before designing and building a camper that you might wish, down the road, you had made a bit taller.