Are you considering the fitment of a small 'fighting butt' Sandy
I ask as finding the balance on a 11' rod can be tricky and in my experience reel weight and general mass in the bottom of the rod is generally helpful.... I'm not talking loads of weight, just enough. Also, your build is likely to be more about quality than most mainstream 11' rods I've picked up, I imagine you'd be looking at lower weight components, minimal whipping and 'all that is required' in epoxy compared to most other builds. If that is a reasonable assumption, then ultimately your rod should be less middle to tip heavy than many an equivalent making the cork size perhaps less critical than it might otherwise be.
So, without the 'wee butt' then I would opt for a longer cork handle.
With the butt, then 7" would most likely be fine.
H