Hey Jason
Well, as most Themes only support 2-3 and sometimes 4 layers deep of navigation, you’re going to have to do it the old fashioned way with Foundations, BootSnap (BootStrap) or Pure…
There was a lady that posted about nov/dec 2015 that was asking for help with their nav system with an Elixir Theme I think, can’t remember the thread but it was manually managing the UL/LI items to make the nav system go deeper.
You could do it the image way and import that image into an iFrame so that it is zoomable with pin drops, but I think that stack is limited in number of pin drops (NOT 100% on that) allowed.
It really depends on what information you or your client wants displayed on the site… Does Family Tree Maker (or whatever management software you are using) allow exporting to HTML?
Brad